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					The Invisible Epidemic: Factors associated with the Late Diagnosis in Thai Youth   1


                 THE INVISIBLE EPIDEMIC:

Factors associated with the Late Diagnosis of HIV in Thai Youth-


                                A Population-Based Study




           A master thesis submitted to the department of International Health

                                   Institute of Public Health

                          In partial fulfillment of the requirements

                 of the graduate school of National Yang-Ming University




                                                By

                                    Netima Cooney, MD

                  Advisor: Chen-Chang Yang, MD, MPH, DrPH.
2                                                                                 C. Netima


                                        ABSTRACT


Objective: It’s believed that there is still a large number of late diagnoses of HIV infection;

whereas the incidence of HIV in young people is significantly increasing around the world.

Our objective is to evaluate the factors that are associated with the late diagnosis of HIV in

young Thai people.

Design: A population-based cross-sectional study in Thailand between 1 January 1997 and 30

June 2006.

Methods: All patients aged 15 to 24 years old reported to the Thailand’s National HIV/AIDS

surveillance system, Bureau of Epidemiology, Department of Disease Control, Ministry of

Public Health in Thailand, were included. Those with perinatal infection and patients with

HIV diagnosed less than six months from the end of the study period were excluded. Subjects

were grouped as late diagnosis and non-late diagnosis of HIV infection. Late diagnosis was

defined as a first HIV positive test within 6 months of AIDS diagnosis.

Results: Of the 23,693 patients studied, 20,529 (86.6%) were late diagnosis. The following

factors were independently associated with late diagnosis of HIV in young Thai people: male

gender; age 20-24 years old; being single; male/female bar worker, office worker, prisoner,

unemployed; those living in central region; rural residence; IPD patients; and those who

received treatments from BMA hospital, university hospital or regional/general hospitals, and

heath services under the Department of Disease Control.

Conclusions: Even though the number of HIV patients has been decreased from year 1997 to

2006, the ratio between late and non-late diagnosis of patient has increased. The results of

this study may suggest changes and improvements to the screening tests, prevention policies,

education programs and help to determine the right target populations. As a result, it will

eventually help decrease the incidence of HIV infection in Thailand.

         Keywords: AIDS HIV infection, late diagnosis, young people, Thailand
The Invisible Epidemic: Factors associated with the Late Diagnosis in Thai Youth            3


                                       Acknowledgement


       I would like to take this opportunity to thank those individuals and institutes who help

me along these past two years. Without these people’s help, I would not have made it through.

       Firstly, I would like to thank the Bureau of Epidemiology, Department of Disease

Control, Ministry of Public Health (MoPH) in Bangkok, Thailand, especially Dr. Kumnuan

Ungchusak, Dr. Tanarak Plipat, Khun Orapan Sangwonloy, and Khun Phuongtipya Ratanarat

for providing important information and advice.

       Secondly, I would like to express my sincere appreciation to my advisor, Dr. Chen-

Chang Yang, for his superior guidance, encouragement, understanding, and immeasurable

patience to answer my questions, and provide so much help.

       Thirdly, to Dr. Nicole Huang who inspired me to work from the beginning. Without

the inspiration, encouragement and guidance from her, this work presented in this thesis

would not have been possible.

       Fourthly, I would like to thank Professor Song-Lih Huang and the International

Health program, National-Yang Ming University, who gave me this opportunity for

education. Additionally, I would like to thank all my colleges for being incredibly supportive

and giving me so much help here in Taiwan.

       I also would like to thank my lovely family who has always being supportive every

time I called home.

       Last but not least, I would like to especially thank my beloved husband, Sean Cooney

who was always by my side, reviewed my work, was my English teacher, and whose

invaluable support made this thesis possible more than anything else.



                                   TABLE OF CONTENTS

                                                                                          Page
4                                                                     C. Netima


Abstract……………………………………………………………………………………….2

Acknowledgment…………………..…………………………………………………………3

List of Tables………………………………………………………………………………….4

List of Figures……………………………………………………………………………..…6

List of Appendices……………………………………………………………………………7

List of Abbreviations…………………………………………………………………….......8

Chapter 1. Introduction, Background and Significance………………………………....10

1.1 Introduction……………………………………………………………………….……..10

1.2 Background……………………………………………………………………………....13

    1.2.1 AIDS epidemic in Thailand……………………………...……………………………13

    1.2.2 HIV situation in Thai youth………………………...…………………………………14

Chapter 2. Review of the Literature……………………………………………………….15

2.1 Previous studies on late diagnosis of HIV………………………………………...……...15

2.2 Definition of late diagnosis of HIV ………………………………………...…………….15

2.3 Studies in young people…………………………………………………………...……...16

Chapter 3. Research Design and Methods…………………………...……………………17

3.1 Study design……………………………………………………………………………....17

3.2 Data collection…………………………………………………………………………...18

3.3 Thailand’s National HIV/AIDS Surveillance Database……..…………………………..18

3.4 HIV/AIDS surveillance database: Archival and access information……..……………...20

3.5 Study period………………………………………………………………….…………...20

3.6 Study variables……………………………………………....……………….…………..21

3.7 Protect of human subjects………………………………...………...……….…………...22

3.8 Statistical analysis………………………………...………………………………….…..22

3.9 Sensitivity analysis…………………………………………………………………..…...23
The Invisible Epidemic: Factors associated with the Late Diagnosis in Thai Youth       5


Chapter 4. Results………………………………………………………………………..…24

4.1 Study population……….………………………………………...…………………….....24

4.2 Proportion of Late diagnosis and Non-late diagnosis of HIV...……………….................26

4.3 Determinants of Late diagnosis of HIV infection in Thai youth…….....……………....…27

4.4 AIDS-defining illnesses and symptom of patients…….…..……………………………...28

4.5 Sensitivity analysis…………………………………………………………………….…28

Chapter 5. Discussion……………………………………………………………………….31

5.1 Summary of late diagnosis of HIV situation in Thai youth………………………………31

5.2 Gender……………………………………………………………………………………32

5.3 Marital status…………………………………………………………………………….33

5.4 Residence………………………………………………..………………………..........…34

5.5 Injecting drug users………………………………………………..……………..........…35

5.6 Sexual behavior…………………………………………………………………..........…36

5.7 Occupation………………………………………………………………….................…37

5.8 Health care services…………………………………………………………………...…39

5.9 AIDS-defining illnesses………………………………………………………...……...…40

5.10 Policy implication………………………………………………………………………40

5.11 Study limitations……………………………………………………………………...…42

5.12 Conclusion………………………………………………………………………………43

List of References………………………………………………………………………...…44




List of Tables
6                                                                                C. Netima


Table 1. The definitions of late and non-late diagnosis of HIV infection……………………50

Table 2. Main data set variables……………………………………………...………………51

Table 3. Sociodemographic characteristics of study population……………………...……...53

Table 4. Risk factors & health characteristics of study population…………………………..54

Table 5. Proportion of late and non late diagnosis in Thai youth………………………...….55

Table 6. Predictors of Late diagnosis of HIV in Thai youth…………………………………57

Table 7. Number(s) of AIDS-defining illnesses in young patients with late diagnosis,

Thailand, January 1997 – June 2006…………………………………………………………59

Table 8. Predictors of late diagnosis of HIV in young patient aged 15-24 years old, both

unadjusted and adjusted odds ratios, Thailand, 1 January 1997- 30 June 2006 (Changing ‘late

diagnosis’ definition to 2 months)…….……………………………………………….….….60

Table 9. Predictors of late diagnosis of HIV in young patient aged 15-24 years old, both

unadjusted and adjusted odds ratios, Thailand, 1 January 1997- 30 June 2006 (Changing ‘late

diagnosis’ definition to 3 months)…….……………………………………………………...62

Table 10. Predictors of late diagnosis of HIV in young patient aged 15-24 years old, both

unadjusted and adjusted odds ratios, Thailand, 1 January 1997- 30 June 2006 (Changing ‘late

diagnosis’ definition to 12 months)…….…………………………………………………….64




List of Figures
The Invisible Epidemic: Factors associated with the Late Diagnosis in Thai Youth          7


                        late' non-late'
Figure 1. Proportion of ' and '        diagnosis of HIV by year (Thailand, January 1997-

June 2006). ……………………………………………………………………………..……66

Figure 2. Map of HIV prevalence in young Thai patients aged 15-24 years old, Thailand,

January 1997– June 2006…………………………………………...………………………..67

Figure 3. Map A. and B. show the prevalence of HIV in non-late diagnosis and late diagnosis.

Map C. shows the proportion of HIV prevalence in late diagnosis compare to non-late

diagnosis in young patients aged 15 – 24 years old, Thailand, January 1997– June 2006......68

Figure 4. Percentage of patients according to sexual behavior and transmission category,

Thailand, January 1997 – June 2006……………………………...………………………….69

Figure 5. Percentage of patients with late diagnosis of HIV by occupation, Thailand, January

1997 – June 2006…………………………………………………………………….………70

Figure 6. Prevalence of AID-defining illnesses in late presenters, Thailand, January 1997 –

June 2006……………………………………………………………………………………..71




List of Appendices
8                                                                              C. Netima


Appendix A. AIDS surveillance case definition for adults and adolescents used in Thailand

(5th edition)…………………………………………………………………………………..72

Appendix B. 1993 revised classification system for HIV infection and expanded surveillance

case definition for AIDS among adolescents and adults……………………………………81




List of Abbreviations

AIDS                 Acquired immunodeficiency syndrome
The Invisible Epidemic: Factors associated with the Late Diagnosis in Thai Youth     9


ART                    Antiretroviral therapy

AZT                    Zidovudine

BMA                    Bangkok Metropolitan Administration

CBO                    Community-based organization

CDC                    Center for Disease Control and Prevention

HAART                  Highly Active Antiretroviral Therapy

HIV                    Human immunodeficiency virus

IDU                    Injecting drug user

IPD                    Inpatient department

MOPH                   Ministry of Public Health

MSM                    Men having sex with men

NGO                    Non-governmental organization

OPD                    Outpatient department

PHA                    Persons with HIV and AIDS

STI                    Sexually transmitted infection

TB                     Tuberculosis

TYAP                   Thai Youth AIDS Prevention Project

UNAIDS                 Joint United Nation Programme on HIV/AIDS

UNGASS                 United Nations General Assembly Special Session on HIV/AIDS

UNICEF                 United Nations Children’s Fund

VCT                    Voluntary counseling and testing

VD                     Venereal disease

WHO                    World Health Organization

Chapter 1. Introduction, background and Significance


1.1 Introduction
10                                                                                                 C. Netima


        It is generally accepted that HIV has moved out of the high risk groups (injecting drug

users, sex workers, men having sex with men) and into the mainstream population. The HIV

epidemic is now generally spreading among young people (‘young people’ are defined as

people aged 10-24 years old, ‘youth’ are defined as people aged 15 to 24 years old according

to UN*).1 UNAIDS statistics for 2005 showed that half of the 14,000 new HIV infections

daily worldwide occurred in people between the ages of 15-24. Currently, more than 10

million young people are living with HIV/AIDS.2 The World AIDS Campaign 2005-2010

has stated, “Young people will be key, both as a target group of the campaign, but also as

drivers of it.”3

        Young people are the major population in the developing world. They are also highly

vulnerable to HIV infection. This vulnerability comes from a lack of full maturity in social,

mental, and physical aspects. The 2001 United Nations General Assembly Special Session on

HIV/AIDS (UNGASS) committed to ensuring that “By 2005, at least 90%, and by 2010 at

least 95% of young men and women should have access to the information, education,

including peer education and youth-specific education, and services necessary to develop the

life skills required to reduce their vulnerability to HIV infection; in full partnership with

youth, parent, families, educators and health care providers.”4

        The burden that AIDS places on government, society, and family groups is well known.

The debilitation of the younger, and should be stronger, members of society is a double-

edged sword. It not only robs the community of what should be, or would be, the stronger

workers; but also places the burden of support, for those infected with AIDS, back on the rest

of society.

        Like many countries, Thailand has to face the increasing incidence of HIV infection in

young people. Within Thailand the rate of HIV spreading amongst young people is higher


*
    The United Nations General Assembly defined ‘youth’, as those persons falling between the ages of 15 and 24
The Invisible Epidemic: Factors associated with the Late Diagnosis in Thai Youth                         11


than that of the rest of the population.5 The Health Ministry in Thailand has noted that the

rate of HIV infection among teenagers rose during 2002 from 11 to 17%.6 The updated data

by the end of June 2006 from the Epidemiological Information Center (Bureau of

Epidemiology, Department of Disease Control) had shown that the among all 296,024 AIDS

patients, 28,170 were patients aged between 15-24 years old. That is about 9.5% of all AIDS

patients. Unexpectedly, this data also showed that the incidence of AIDS in patients aged

between 15 to 16 years, was on the rise.7

     However, the actual incidence of HIV infection in young Thai people may still be

invisible. Young people often carry HIV for years without knowing that they are infected.

Globally, the vast majority of youth have little understanding of HIV transmission or how to

protect themselves against HIV. Recently UNAIDS statistics showed that only 33 percent of

young men and only 20 percent of young women aged 15-24 can correctly identify

prevention methods of HIV transmission. Although the Declaration of Commitment on

HIV/AIDS aimed for 90% of young people to be knowledgeable about HIV by 2005, surveys

indicated that fewer than 50% of young people worldwide have achieved comprehensive

knowledge levels.8 In addition, young people face serious obstacles to accessing medical care,

including fear that their privacy will not be respected; embarrassment; distance to services,

and health providers who are reluctant to serve adolescents.9 As a result, the epidemic spreads

among the young people themselves and the general population. To further complicate

matters, there are signs of increased unsafe sexual behavior among young people in Thailand.

It is estimated that only 20% to 30% of sexually-active young people are using condoms

consistently.10

     Many believe that the early detection of HIV will not only help in the prevention of the

spread of HIV, but with proper and early medical treatment, allow those individuals to


years inclusive. This definition was made for International Youth Year, held around the world in 1985.
12                                                                                    C. Netima


prolong the onset of opportunistic infections and reduce early mortality.11, 12 This allows

those individuals to continue to benefit society for a longer period of time prior to their

debilitation. In order to develop an effective policy to decrease the number of late diagnosis

of HIV, it is necessary to firstly access the factors associated with the late diagnosis of HIV in

youth.

         Previous studies have shown that many factors, such as male gender; older age;

heterosexuality; and non-white, Hispanic or African ethnicity are associated with increasing

risk of late diagnosis of HIV.13-19 However, those factors specific to youth remain unclear.

Moreover, studies targeting incidences of HIV in the youth are limited. This study will be the

first one to address those factors associated with late diagnosis of HIV in Thai youth. .



1.2 Background

1.2.1 AIDS epidemic in Thailand

     Thailand is one of the successful countries in regards to the effectiveness in preventing

and decreasing the incidence of HIV/AIDS epidemic. The number of new HIV infections has

fallen from 143,000 in 1991 to 19,000 in 2003.20 However, currently HIV/AIDS is still a

major cause of death among Thais, especially young adults. In 2003, over 53,000 people died

of AIDS, twice the number of deaths due to traffic accidents. The AIDS epidemic in Thailand

has a huge cost both socially and economically. A previous report estimates that Thailand

loses over 40 billion baht (US$ 1 billion) a year in forgone income due AIDS illness and

death.21

     The first case of AIDS in Thailand was reported in 1984 in a 24-year-old homosexual

man who had returned from overseas. 22 After that, there was evidence that HIV transmission

increased during late 1980s. The first wave of transmission occurred in 1988, and the

prevalence of HIV in injecting drug users dramatically increased from 1% to 43% in a single
The Invisible Epidemic: Factors associated with the Late Diagnosis in Thai Youth              13


year.23 In 1989, the second wave of infection spread among female sex workers.24

Subsequently, the later waves of infection spread among male clients as well as their wives,

partners and children.25

     The Thai government responded to the epidemic by launching many intervention

programs and policies regarding HIV prevention, such as the 100 percent condom

program23and mother-to-child transmission prevention program.26 Government forethought

helped to establish the National HIV/AIDS Surveillance System, Bureau of Epidemiology,

Ministry of Public Health in Thailand in 1983.27 This has been extremely beneficial in terms

of recognizing the epidemic, instituting policies, planning, and programs to help with HIV

prevention.



1.2.2 HIV situation in Thai youth

     While there have been many efforts in order to control the HIV/AIDS epidemic in high

risk groups such as female sex workers and injecting drug users, the infection finally

substantially spread to young people in late 1990s.28,    29
                                                               A study in Northern Thailand found

that most of HIV transmission occurs during adolescence or young adulthood.29 The

vulnerability to HIV in these age groups might be explained by various reasons. Firstly,

premarital sex has become more common among young Thais.8 There is also an increase in

premarital sex among women with a partner whose sexual networks include female sex

workers.30 Secondly, unsafe sexual behaviors have become the major problem among this age

group. A previous study reported that only 20-30% of sexually active young people are using

condoms consistently.10 Thirdly, drugs and substance abuse in youth is also a factor that leads

to the spreading of HIV epidemic.31 Another study found there are associations between drug

and alcohol use and a history of sexual intercourse in young Thai females.32 Finally, the most

important factor is the lack of awareness of HIV/AIDS among this age group. The same study
14                                                                                 C. Netima


showed that the majority of sexually active young females do not perceive themselves to be

at high risk for acquiring HIV and sexually transmitted infection (STI) in the future.32 It is

thought that around 85% of Thai youth do not see HIV as something that they should be

concerned about, even though 70% of all STI cases in Thailand occur among this group.33

     Many studies have focused on the risk factors related to HIV infection, such as sexual

behavior, education, and socioeconomic status.30-33 Those studies consistently indicated that

there is still an “unawareness” of HIV infection. As many young Thai females and males are

engaged in high risk behaviors, it’s believed that the incidence of HIV infection will be high

among this age group. Nevertheless, according to the report from the Bureau of

Epidemiology, Ministry of Public Health, only 9.5% of HIV patients are youth, which was

likely to be underreported 7

     Given a hypothesis of lack of awareness of HIV infection in Thai youth, it is expected

that the number of late diagnosis of HIV in Thai youth will be high because young people

often carry HIV for years without knowing that they are infected. If the hypothesis is true,

then expanding the knowledge and the awareness of HIV among youth will be a crucial issue

for Thailand or any country in future control of the HIV/AIDS epidemic.




Chapter 2. Review of the Literature


2.1 Previous studies on late diagnosis of HIV
The Invisible Epidemic: Factors associated with the Late Diagnosis in Thai Youth                  15


     Many studies have investigated the risk factors for acquiring HIV infection, the groups

at risk, and the ways to increase the sensitivity of HIV tests, but little is known about the

factors associated with a delayed diagnosis of HIV infection.

     Most of the published studies were conducted in western, developed countries, such as

UK,13, 14 France,15 Italy,16 Spain,17 Sweden,18 Ireland14 and USA.19 Only few studies had been

conducted in Asia-Pacific countries such as Hong Kong,34 Victoria (Australia),35 or in

developing countries, such as French Guiana.36 In Thailand, there have been no studies

identifying the factors associated with late diagnosis of HIV. Most of previous studies

focused on the risk factors for HIV infection.

     Of the above studies that focused on late diagnosis of HIV, most showed that the

percentage of late diagnosis of HIV infection remains high. These studies showed the figures

of late diagnosis of HIV ranging from 19% to 52% of all HIV infection cases. This suggests

the importance of understanding the factors related to late diagnosis of HIV, in terms of

prevention of disease transmission. The studies further suggested an increased risk of late

diagnosis of HIV in populations of male gender; older age; heterosexuality; and non-white,

Hispanic or African ethnicity. For men having sex with men (MSM), an Italian study16 found

that this would increase the risk. In contrast, a study in Hong Kong34 found MSM to be at

lower risk for late diagnosis. Most studies do show consistent results that injecting drug users

(IDUs) are at lower risk for late diagnosis.16, 18



2.2 Definition of late diagnosis of HIV

     The definition of late diagnosis of HIV infection varies, and depends on the definition of

“late”. Is “late”, too late for the patient to respond to treatment, or is “late” too late to prevent

the spread and propagation of the disease due to the lack of knowledge of the infection?

Because of the difficulty in defining “late” there has been no universal definition.
16                                                                                       C. Netima

                                                                                               14, 17,
       Some studies used CD4 count less than 200/µL at diagnosis to define late diagnosis.

36
     Other studies defined late diagnosis according to the duration from the first HIV diagnosis

                        16, 18, 35
until AIDS diagnosis.                This period ranged between eight weeks to one year. This study

used 6 months or less as a definition of late diagnosis. The median duration from HIV
                                                              37
infection to AIDS diagnosis is approximately 11 years,             as such, 6 months or less between

AIDS presentation and a positive HIV test can be considered to be late diagnosis.



2.3 Studies in young people

       Among previous studies, most of them studied AIDS patients in general, without

emphasis on specific age groups. There have been no studies focusing on young patients.

Young people nowadays represent half of the new HIV infections occurring worldwide,2 as

such, it is more important than ever to understand the exposure, transmission and infection of

this group. This study aimed to understand the factors associated with late diagnosis of HIV

in young Thai people, in order to help those individuals in terms of medical, social and

psychological points of view. Furthermore, for public health, this study could be used as a

reference. It would then be useful for planning prevention and/or intervention strategies for

specific target groups. This in turn, would then be helpful in decreasing the incidence of HIV

infection.




Chapter 3. Research design and Methods
The Invisible Epidemic: Factors associated with the Late Diagnosis in Thai Youth                17


3.1 Study design

     This was a population-based cross-sectional study. The study population was HIV-

positive patients between the ages of 15 to 24 years old in Thailand. There was no sampling,

because the entire population was studied. The 2006 data from the Bureau of Epidemiology

showed that among 296,024 AIDS patients across Thailand, 28,170 were aged between 15 to

24 years old or 9.5% of all AIDS patients.7

     AIDS was defined as those HIV-positive patients who presented with symptoms as

defined by the AIDS Surveillance Case Definition for Adults and Adolescents used in

Thailand (Appendix A).38 The disease classification system is basically an adaptation of the

U.S. Center for Disease Control (CDC) 1993 definition (Appendix B).39 The latest version is

the 5th edition which was published in year 2004. In order to diagnose patients with AIDS, a

test for HIV antibody must give a positive result. AIDS patients will be classified in to three

categories as follows:

1) All HIV infected persons who had sign/symptom of at least one disease out of the twenty-

eight diseases as described in AIDS indicative diseases.

2) All HIV-infected persons who had less than 200/µL CD4+ T-lymphocytes, or a CD4+ T-

lymphocyte percentage of total lymphocytes of less than 15, at least twice in separate tests.

3) Patients who were infected via vertical transmission (pediatric AIDS).

     In order to decrease the bias from misclassification, patients perinatally infected with

HIV were excluded, due to faster disease progression40 and different CD4 profiles.41,           42



Moreover, we also excluded patients who were reported as HIV-positive, but did not develop

AIDS within the last 6 months of the study period. Those patients might have belonged to the

late or non-late diagnosis groups.
18                                                                                  C. Netima


     The study further distinguished the population by early or late diagnosis of AIDS. The

first group comprised patients with late diagnosis, while the second group was those who

were not late diagnosis. The definition of late and non late diagnosis were shown in table 1.




3.2 Data collection

     This study was conducted by using the national HIV/AIDS surveillance data from the

Bureau of AIDS, TB and STIs, Bureau of Epidemiology, Department of Disease Control,

Ministry of Public Health (MoPH) in Bangkok, Thailand.



3.3 Thailand’s National HIV/AIDS surveillance system

     The National HIV/AIDS surveillance system in Thailand was established in 1983.27 The

first HIV-positive case was reported in 1984. Since its inception, the system has been further

developed and adapted to provide the best accuracy and efficiency of data collection for HIV-

positive patients. It aims to understand the severity and the significance of the problem; the

epidemiology of HIV/AIDS according to time, place, person, and other related factors; and

the needs of health care services, in order to treat and prevent the diseases.



3.3.1 Feature of HIV/AIDS surveillance system

     The main feature of the HIV/AIDS surveillance program is that it is a hospital-based

system. Every HIV-positive patient from both public and private health care services in

Thailand will be reported and will be followed continuously.



3.3.2 Target population

     The target population of the surveillance system includes those patients who received

care from public or private health care services, and presented symptoms of HIV or AIDS as
The Invisible Epidemic: Factors associated with the Late Diagnosis in Thai Youth            19


defined by the Thai AIDS Surveillance Case Definition for Adults and Adolescents (5th

edition, Appendix A).



3.3.3 HIV/AIDS Surveillance Network

     All health care service providers, including both public and private institutes, have a

duty to report HIV/AIDS cases. Provincial public health offices and department of Health

offices act as the centers of the surveillance network at a provincial level. The Offices of

Disease Prevention and Control 1st to 12th are the centers at the regional level and the Bureau

of Epidemiology, Department of Disease Control, Ministry of Public Health is the center of

surveillance system at the country level. Thus, the information is transferred from province to

region to country. If any mistakes/omissions are found at the final analysis at country level,

the Bureau of Epidemiology, Department of Disease Control will send the file back to the

original province in order to correct the data.



3.3.4 HIV/AIDS surveillance Tools

     AIDS case reporting forms; 506/1 and 507/1.

     HIV test reporting form

     AIDS case report E1/1

     AIDS surveillance case definition for adults and adolescents (5th edition)

     AIDS code book

     Computer software AIDS506

     Laboratory record

     Counseling record

     OPD (outpatient department) card

     Medical chart or IPD (inpatient department) chart
20                                                                                      C. Netima


     ICD 10



3.3.5 Variables in the database

     Socio-demographic data, such as age, gender, national ID number, name code,

occupation, and nationality, etc.

     Illness history such as the date of illness, date of treatment and patients’ status.

     Risk factors of HIV infection such as sexual transmission, injecting drugs, etc.

     AIDS-defining illness and symptom of patients

     Health care services information.



3.4 HIV/AIDS surveillance database: Archival and access information

     Approval to conduct this study and access to the Thailand HIV/AIDS surveillance

database was provided by the Ministry of Public Health in Thailand. Data was compiled and

archived at the Bureau of Epidemiology, Department of Disease Control, Ministry of Public

Health (MoPH) in Bangkok, Thailand.

     Data was available from “AIDS097” file, which contained the dataset variables. There

were 86 fields in the database. The main variables used in this study were shown in Table 2.



3.5 Study period

     The analysis included all cases diagnosed between 1 January 1997 and 30 June 2006.

During this period there were significant changes regarding the use of antiretroviral therapy.

     In 1997, HAART (Highly Active Antiretroviral Therapy, an effective HIV treatment

that involves the combination of three or more drugs) was not yet available for patients.

There was a randomized controlled trial to study the provision of short-course AZT
The Invisible Epidemic: Factors associated with the Late Diagnosis in Thai Youth             21


(zidovudine) to prevent perinatal transmission of HIV in Bangkok.43, 44 By 1999, AZT had

been used in most hospitals in Thailand.45

     In 2000, HAART was introduced to Thailand.20 There was a significant reduction in the

number of people dying from AIDS thereafter. Additionally, there has been a large global

focus on HIV infection in young patients since 2001, as seen in the 2001 UN General

Assembly Special Session on HIV/AIDS.4

     In 2003 the Thai government made an official commitment to ensuring adequate

treatment for all people living with HIV, and set targets to improve treatment access. HAART

was included in Government’s universal health care scheme (30 baht health scheme),

allowing patients to have free access to antiretroviral therapy.5

     Thus, in order to understand whether the availability of antiretroviral therapy has an

effect on young people’s behaviors of seeking health care, we classified the study period in to

three periods, namely1997-1999, 2000-2002 and 2003-2006.



3.6 Study variables

3.6.1 Dependent variables

     The phenomenon of late diagnosis of AIDS patients was treated as the dependent

variable.



3.6.2 Independent variables

     The following variables were considered as possible determinants or correlates of late

diagnosis of HIV:

1. Sociodemographic data such as age, gender, marital status, race, birthplace, occupation

2. HIV exposure category such as injecting drug users (IDUs), sexual transmission,

other/undetermined risk (including blood transfusion);
22                                                                                  C. Netima


3. Sexual orientation: heterosexual, homosexual, bisexual;

4. Treatment centers were classified into groups, such as community hospitals outside

Bangkok; regional/general hospitals outside Bangkok; university hospitals; Bangkok

Metropolitan Administration (BMA) hospitals, private hospitals/clinics; hospitals under

Department of Disease Control; and other hospitals, including hospitals under Department of

Correction, Department of Health, Department of Medical Services, Ministry of Public

Health, Ministry of Defense, Ministry of Inferior and other ministries, Provincial Public

Health Offices, Thai Red Cross, and State Enterprises.

5. AIDS-defining illness


3.7 Protection of Human Subjects

     Strict guidelines protecting patients’ anonymity as issued by the Ministry of Public

Health were followed.



3.8 Statistical analysis

     A Chi-squared test for trend was applied to determine the linear trend in the proportion

of patients with late diagnosis of HIV by year from 1997 to 2006. Comparisons of the

characteristics of patients with late diagnosis and patients with non-late diagnosis were

performed using Chi-squared test and student’s t-test. Multivariate logistic regression models

were used to identify the factors that were independently associated with late diagnosis of

HIV. A p value of < 0.05 was considered statistically significant. All statistical analyses were

performed using the Statistical Package for Social Science (SPSS, version 13.0, SPSS inc.,

Chicago, IL).
The Invisible Epidemic: Factors associated with the Late Diagnosis in Thai Youth              23


3.9 Sensitivity analysis

       In order to confirm the validity of the study, we changed the definition of late diagnosis

from 6 months to 2, 3 and 12 months. These durations have been used in previous studies.13,
14, 16, 18
             We then compared the results to see whether they were consistent.
24                                                                                 C. Netima


Chapter 4. Results


4.1 Study population

     During 1 January 1997 and 30 June 2006, 23,721 young patients aged 15 to 24 years old

were reported to the Bureau of Epidemiology, Department of Disease Control, Ministry of

Public Health (MoPH) in Thailand. Among them, 23,693 (99.8%) were eligible for the study.

The reasons for exclusion were: vertical transmission (14 patients), reporting errors or

inconsistency (i.e. the date of death was prior to the date of HIV treatment; 12 patients) and

patients with HIV diagnosed less than 6 months from the end of the study period without

developing AIDS (1 patient).

     Even though the number of HIV-infected patients has been decreasing from year 1997 to

2006, the proportion between late and non-late diagnosis of patient has increased (Figure 1).

During the study period, there were 20,528 (86.6%) late diagnoses and 3,165 (13.4%) non-

late diagnoses of HIV infection.

     The mean age of patients was 22.3 years. There were 11,370 (48%) males and 12,323

(52%) females. Thai nationals represented 97.6% of the study population, while 1.4% were

others nationalities, and 1.0% with unknown nationality. Eleven thousand and eleven (46.5%)

patients were single and 10,703 (45.2%) were married. There were 6,917 (29.2%) people

living in the central region of Thailand, 6,261 (26.4%) in the northern region, 5,025 (21.2%)

in the northeastern region, 3,087 (13%) in the southern region and 2,403 (10.2%) in the

eastern region (Table 3). Most of the patients came from Bangkok, Chiang Mai, Chiang Rai,

Rayong and Payao provinces, accounting for 10.5%, 5.3%. 4.8% 3.4% and 3.3% respectively

(Figure 2). Of note, these provinces also represented major tourist attraction and sex trade

areas in Thailand.

     In addition, the proportion of late diagnosis of HIV versus non-late diagnosis was higher

in the provinces that had a low prevalence of HIV. In contrast, in provinces that had a high
The Invisible Epidemic: Factors associated with the Late Diagnosis in Thai Youth         25


prevalence, for example Chiang Mai, the proportion of late diagnosis of HIV was lower when

compared to non-late diagnosis. However, Bangkok was shown to have a high prevalence of

HIV, together with the high proportion of late diagnosis (Figure 3).

     Regarding the occupation for this age group, 11,771 (49.7%) of patients worked as

laborers, 4,408 (18.6%) were classified as farmers, 1,779 (7.5%) had no job, 1,760 (7.4%)

were housewives, 708 (3%) were merchants, and the rest 3,267 (13.8%) were other

occupations (Table 3). There were 649 (2.7%) students who were diagnosed with HIV/AIDS,

377 (58%) of this group were studying in university or college, 98 (15.1%) were secondary

school students, 81 (12.5%) were studying postgraduate, 66 (10.2%) were primary school

students, and 27(4.2%) were studying adult education.

     Patients were classified into three categories according to the HIV/AIDS diagnosis: 1)

18,206 (76.9%) were AIDS patients; 2) 5,482 (23.1%) were symptomatic HIV; and 3) 5 (0%)

were asymptomatic HIV patients. Overall, 42.4% received treatments from regional and

general hospitals, 30.7% from community hospitals, 6.8% from Bangkok Metropolitan

Administration (BMA) hospitals, 5.4% from hospitals under the Department of Disease

Control, 3.4% from University hospitals, 3.0% from clinics/private hospitals, 6.5% from

other hospitals By June 2006, 22.1% of the study patients had died (Table 4).

     Regarding the risk factors of transmission, 86.8% contacted HIV via sexual transmission

and 5.7% were IDUs. Of 23,693 patients, 20,546 (86.7%) were heterosexual, 225(1.0%)

homosexual, 69 (0.3%) were bisexual, and 2,385 (12%) were unknown. In addition, persons

that were reported as homosexual had a higher proportion of the use of injecting drugs, when

compared to other sexualities (Figure 4).
26                                                                                 C. Netima


4.2 Proportion of late diagnosis and non-late diagnosis of HIV infection

     In univariate analyses (Table 5), the proportion of late presenters was higher in men than

in women (88.6% versus 84.9%; P <0.001). The proportion of late presenters was

significantly increased by age (81.7% among patients aged 15-16 years old, 84.4% among

those aged 17-18 years old, 83.7% among age group 19-20 years old, 86.8% among age

group 21-22 years old, and 87.4% among age group 23-24 years old; p <0.001). For marital

status, 89.6% of patients who reported being separated were late presenters, compared with

88.9% for patients who were single, 84.6% for patients who were married, 84.2% for patients

who were divorced and 83.6% for patients who were widowed.

     Some 92.4% of the patients who lived in the central region of Thailand were late

presenters, compared with 91.1% of the patients who lived in the southern region, 83.6% of

the patients who lived in the northeastern region, 82.7% of the patients who lived in the

northern region, and 80.9 % of the patients who lived in the eastern region (p <0.001).

     Among Thais, there were differences in the proportion of late presenters according to the

patients’ occupation. The proportion of late presenters within various occupation categories

was as follows: bar worker, 96.9%; prisoner, 96.6%; office worker, 95.3%; unemployment,

91.4%; housewife, 88.5%; merchant, 87.1%; laborer, 86.3%; civil servant, 86.2%; sex worker,

85.3%; business owner, 84.2%; and farmer, 83.4% (p <0.001).

     In the comparison between different occupations, several occupations stand out

statistically as having a higher percentage of late diagnosis. These were male/female bar

worker, office worker, prisoner, those who had no job, student and housewife, and

miscellaneous occupations (Figure 5).

     The proportion of late presenters among groups with risk factor of HIV infection was

91% among IDU patients, 86.3% via sexual transmission and 95.2% among other risk factors

(p<0.001).
The Invisible Epidemic: Factors associated with the Late Diagnosis in Thai Youth         27


     The percentage of late presenters was higher in those patients admitted to inpatient

departments (IPD) than those patients treated in outpatient departments (OPD) (90.2% versus

79.4%; p <0.001). Ninety-nine point six percent of patients received treatment from BMA

hospital were late presenters, compared with 91.1% of patients received treatment from

university hospital, 89.3% from health services under the Department of Disease Control,

87.4% from regional/general hospital, 83.9% from private/hospital/clinic, and 80.5% from

community hospital (p<0.001).

     The proportion of late presenters did not vary with race or sexual orientation, such as

heterosexuality, homosexuality and bisexuality.



4.3 Determinants of late diagnosis of HIV infection in Thai youth

     In multivariate analyses (Table 6), being a late presenter was independently associated

with male gender (OR 1.24; 95% CI: 1.13-1.36; p< 0.001); age group 21-22 years old (OR

1.52; 95% CI: 1.07-2.14; p= 0.02), age 23-24 years old (OR 1.61; 95% CI: 1.14-2.26; p=

0.01); being single (OR 1.18; 95% CI: 1.07-1.30; p< 0.001); male/female bar worker (OR

5.19; 95% CI: 1.25-21.53; p= 0.02), office worker (OR 2.58; 95% CI: 1.33-5.00; p= 0.01),

prisoner (OR 2.31; 95% CI: 1.35-3.96; p< 0.01), and jobless patients (OR 1.32; 95% CI:

1.09-1.58; p<0.01); patients who lived in the central region (OR 2.40; 95% CI:2.14-2.73; p<

0.001), the northeastern region (OR 1.46; 95% CI: 1.31-1.63; p< 0.001), and the southern

region (OR 2.46; 95% CI: 2.11-2.86; p< 0.001; using the northern region as the reference);

people who lived in rural residence (OR 1.15; 95% CI: 1.02-1.31; p= 0.02); IPD patients(OR

2.30; 95% CI: 2.12-2.50; p< 0.001); those who received treatments from BMA hospital (OR

57.51; 95% CI: 27.23-121.49; p< 0.001), university hospital (OR 2.57; 95% CI: 1.97-3.37; p<

0.001), regional/general hospital (OR 1.34; 95% CI: 1.34-1.60; p< 0.001), and heath services

under the Department of Disease Control (OR 1.47; 95% CI: 1.20-1.80; p< 0.001; using
28                                                                                  C. Netima


community hospital as the reference). Private hospitals/clinics were associated with non-late

diagnosis of HIV, as compared to community hospitals (OR 0.72; 95% CI: 0.57-0.92; p=

0.01).

     The availability of highly active antiretroviral therapy did not seem to be associated with

an earlier HIV diagnosis. There was no improvement in the early detection of HIV infection

in the past 9 years.



4.4 AIDS-defining illnesses and symptom of patients

     Among patients with late diagnosis, 3,458 (16.8%) had no AIDS-defining illness, 14,166

(69.0) had a single illness, 2,397 (11.7%) had two illnesses, and 507 (2.5%) had multiple

AIDS-defining illnesses (Table 7). People who had at least two diseases were associated with

late diagnosis compared to those who had none or one AIDS-defining illness (OR 86.36; p<

0.001 and OR 92.06; p< 0.001, respectively).

     Among late presenters, the most common AIDS-defining illnesses were: mycobacterium

tuberculosis (26.6%), Pneumocystis carinii pneumonia (21.3%), wasting syndrome (19.3%),

Cryptococcosis (13.6%) and esophageal candidiasis (4.3%, Figure 6). The prevalence of

AIDS-defining illnesses was less than one percent among non-late presenters.



4.5 Sensitivity Analysis

     After changing the definition of late diagnosis to 2, 3 and 12 months, the findings were

largely similar to those of the “6-month” definition.

     Table 8 showed the results of using the “2-month” definition. Among 23,963 patients,

20,483 (86.5%) were patients with late diagnosis, and 3,165 (13.5%) were non-late diagnosis.

     Factors independently associated with late diagnosis of HIV were: male gender (OR

1.25; 95% CI: 1.14-1.37; p< 0.001); age group 21-22 years old (OR 1.47; 95% CI: 1.04-2.27;
The Invisible Epidemic: Factors associated with the Late Diagnosis in Thai Youth          29


p= 0.03), age 23-24 years old (OR 1.54; 95% CI: 1.09-2.16; p= 0.01); being single (OR 1.17;

95% CI: 1.06-1.29; p< 0.01); male/female bar worker (OR 5.22; 95% CI: 1.26-21.65; p=

0.02), office worker (OR 2.33; 95% CI: 1.23-4.38; p= 0.01), prisoner (OR 2.31; 95% CI:

1.35-3.95; p< 0.01), and jobless patients (OR 1.25; 95% CI: 1.05-1.50; p= 0.01); patients who

lived in the central region (OR 2.47; 95% CI: 2.18-2.80; p< 0.001), the northeastern region

(OR 1.51; 95% CI: 1.36-1.69; p< 0.001), and the southern region (OR 2.51; 95% CI: 2.16-

2.92; p< 0.001; using the northern region as the reference); people who lived in rural

residence (OR 1.16; 95% CI: 1.02-1.31; p= 0.02); IPD patients (OR 2.29; 95% CI: 2.10-2.48;

p< 0.001); those who received treatments from BMA hospital (OR 59.50; 95% CI: 28.17-

125.68; p< 0.001), university hospital (OR 2.57; 95% CI: 1.97-3.35; p< 0.001),

regional/general hospital (OR 1.48; 95% CI: 1.35-1.62; p< 0.001), and heath services under

the Department of Disease Control (OR 1.50; 95% CI: 1.22-1.83; p< 0.001). Private

hospitals/clinics were associated with non-late diagnosis of HIV as compared to community

hospitals (OR 0.74; 95% CI: 0.59-0.94; p= 0.01).

     Table 9 revealed the findings of multivariate analyses by defining late diagnosis of HIV

to 3 months. Among the 23,963 patients, 20,500 (86.5%) were patients with late diagnosis;

3,193 (13.5%) were non-late diagnosis. Factors independently associated with late diagnosis

of HIV included: male gender (OR 1.25; 95% CI: 1.13-1.37; p < 0.001); age group 21-22

years old (OR 1.49; 95% CI: 1.06-2.11; p = 0.02), age 23-24 years old (OR 1.57; 95% CI:

1.11-2.21; p= 0.01); being single (OR 1.18; 95% CI: 1.07-1.30; p< 0.001); male/female bar

worker (OR 5.19; 95% CI: 1.25-21.53; p= 0.02), office worker (OR 2.58; 95% CI: 1.33-5.01;

p< 0.01), prisoner (OR 2.31; 95% CI: 1.35-3.95; p< 0.01), and jobless patients (OR 1.29;

95% CI: 1.07-1.55; p= 0.01); patients who lived in the central region (OR 2.44; 95% CI:

2.16-2.77; p< 0.001), the northeastern region (OR 1.50; 95% CI: 1.35-1.68; p< 0.001), and

the southern region (OR 2.44; 95% CI: 2.16-2.77; p< 0.001; using the northern region as the
30                                                                               C. Netima


reference); people who lived in rural residence (OR 1.16; 95% CI: 1.02-1.31; p= 0.02); IPD

patients (OR 2.29; 95% CI: 2.11-2.49; p< 0.001); those who received treatments from BMA

hospital (OR 58.98; 95% CI: 27.92-124.58; p< 0.001), university hospital (OR 2.56; 95% CI:

1.96-3.34; p< 0.001), regional/general hospital (OR 1.47; 95% CI: 1.35-1.61; p< 0.001), and

heath services under the Department of Disease Control (OR 1.49; 95% CI: 1.22-1.82; p<

0.001). Private hospitals/clinics were associated with non-late diagnosis of HIV as compared

to community hospitals (OR 0.73; 95% CI: 0.58-0.93; p= 0.01).

     Table 10 showed the findings of changing the definition of late diagnosis to 12 months.

Among the 23,682 eligible patients, 20,564 (86.8%) were patients with late diagnosis, and

3,118 (13.2%) were non-late diagnosis. Independent factors of late diagnosis of HIV included:

male gender (OR 1.23; 95% CI: 1.12-1.36; p< 0.001); age group 21-22 years old (OR 1.49;

95% CI: 1.05-2.12; p= 0.02), age 23-24 years old (OR 1.58; 95% CI: 1.11-2.23; p= 0.01);

being single (OR 1.19; 95% CI: 1.08-1.31; p< 0.001); male/female bar worker (OR 5.08;

95% CI: 1.22-21.06; p= 0.03), office worker (OR 2.55; 95% CI: 1.31-4.95; p= 0.01), prisoner

(OR 2.48; 95% CI: 1.43-4.32; p< 0.01), and jobless patients (OR 1.33; 95% CI: 1.10-1.60; p<

0.01); patients who lived in the central region (OR 2.38; 95% CI: 2.10-2.70; p< 0.001), the

northeastern region (OR 1.44; 95% CI: 1.29-1.60; p< 0.001), and the southern region (OR

2.45; 95% CI: 2.10-2.86; p< 0.001; using the northern region as the reference); people who

lived in rural residence (OR 1.15; 95% CI: 1.01-1.30; p= 0.03); IPD patients (OR 2.31; 95%

CI: 2.13-2.51; p< 0.001); those who received treatments from BMA hospital (OR 55.76; 95%

CI: 26.40-117.79; p< 0.001), university hospital (OR 2.53; 95% CI: 1.93-3.30; p< 0.001),

regional/general hospital (OR 1.44; 95% CI: 1.32-1.58; p< 0.001), and heath services under

the Department of Disease Control (OR 1.45; 95% CI: 1.18-1.77; p< 0.001). Private

hospitals/clinics were associated with non-late diagnosis of HIV as compared to community

hospitals (OR 0.70; 95% CI: 0.56-0.89; p< 0.01).
The Invisible Epidemic: Factors associated with the Late Diagnosis in Thai Youth            31


Chapter 5. Discussion


5.1 Summary of late diagnosis of HIV situation in Thai youth

     This study highlights that while the incidence of HIV is declining, the proportion of late

diagnosis of HIV in young Thai people has increased dramatically over the past nine years.

Moreover, late diagnosis of HIV has increased despite an increasing number of prevention

and awareness programs promoted by both government and non-governmental organizations

(NGOs), which were specifically aimed at young Thai people; and the availability of HARRT

(Highly Active Antiretroviral Therapy) in Thailand.

     In order to interpret the trend of late diagnosis of HIV, many factors need to be

considered. One of the important factors that might affect the real trend is the improvement of

AIDS diagnosis. In Thailand, there have been improvements of AIDS diagnosis over the past

decade, including AIDS-defining illnesses and CD4 count testing. The definition and

diagnosis of “AIDS” was adapted in 2004 in the AIDS Surveillance Case Definition for

Adults and Adolescents used in Thailand.38 It aimed to increase the sensitivity in detecting

AIDS by adding three diseases (i.e. nocardiosis, rhodococcosis, and serious bacterial

infection, recurrent or multiple) to the twenty-five AIDS indicative diseases listed in 1993.

However, the prevalence of those diseases among our study population was 0, 0.3 and 0

percent respectively. Additionally, the trend was increasing in both the periods before and

after the change of AIDS definition (i.e. 1997-2003 and 2004-2006 period). After adjusting

for AIDS-defining illnesses, we still found a significantly increased trend of late diagnosis

from 1997 to 2006.

     CD4 count is another criterion to define AIDS and “AIDS patients” were defined for all

HIV-infected persons who had CD4+ T-lymphocytes less than 200/µL, or a CD4+ T-

lymphocyte of less than 15% of total lymphocytes at least on two occasions. Another study
32                                                                                    C. Netima


showed that the median percentages of eligible patients receiving CD4 testing in 2002, 2003,

2004, and 2005, were 24%, 76%, 77%, and 95%, respectively.46 Our study in Thai youth

found only 0.5% of patients had CD4 counts of less than 200/µL. This meant that most youth

patients did not have CD4 count data and were diagnosed via a positive HIV test plus at least

one AIDS-defining illness. Thus, the higher proportion of late diagnosis of HIV over the

study period was not likely to be affected by the application of CD4 data in AIDS diagnosis.

     The study showed that 86% of young Thai people aged 15 to 24 years old had delayed

diagnosis of HIV. This proportion of late diagnosis is higher than that in adults. Other studies

of general population showed the figures of late diagnosis of HIV ranging from 19% to 52%

of all HIV-infected cases.13-19 Even though this is the first study regarding HIV in young Thai
                                             19, 47
people, the evidence from two U.S. studies            confirmed the result that people aged 13-29

years old are significantly associated with late diagnosis of HIV. However, the factors

associated with late diagnosis of HIV among this age group are unclear. Our study showed

that the following factors were independently associated with late diagnosis of HIV in young

Thai people: male gender; age 20-24 years old; being single; male/female bar worker, office

worker, prisoner, unemployed; those living in central region; rural residence; IPD patients;

and those who received treatments from BMA hospital, university hospital or

regional/general hospitals.



5.2 Gender

     Similar to previous studies in Honk Kong,34 France,15 Italy,16 Spain,17 and US,19 late

diagnosis of HIV in young Thai people were more common in male than female gender.

There are many possible reasons that might explain this. Firstly, males in this age category

have less utilization of health care services.49, 50 A study showed men, especially younger

men, were significantly less likely than women to receive certain preventive services.49 In
The Invisible Epidemic: Factors associated with the Late Diagnosis in Thai Youth          33


addition, a study regarding treatments of persons with HIV and AIDS (PHAs) in Thailand,

illustrated that women were more likely to benefit from the health care system than men, and

were more likely to be open about their HIV status than men.50 Secondly, in Thailand there is

a policy encouraging screening for HIV during pregnancy. The Ministry of Public Health

established the national policy regarding prevention of perinatal HIV transmission in 1999.45

The policy components include voluntary counseling and HIV testing for all pregnant women,

AZT for all HIV-infected pregnant women starting at 34 weeks gestation, AZT for all

children born to HIV-infected women, and infant formula for 12 months to replace

breastfeeding. The program has been highly successful and has reached more than 950,000

pregnant women to date. Based on national data collected in 2002, 98% of pregnant women

received some antenatal care. Among women who delivered, 96% had an HIV test.51

Therefore, child-bearing women will have higher accessibility and opportunity to have early

HIV detection than men. Finally, the Thai government has a HIV surveillance policy related

to female sex workers.27 Female sex workers are encouraged and counseled to receive HIV

screening tests. In addition, there is an increase in awareness of disease among female sex

workers along with the policies in work places, such as condom use. As part of the Venereal

Disease (VD) Control Program of the Ministry of Public Health, the sex establishments are

registered and VD clinic officers visit them periodically. The owner of the sex establishment

also sends the prostitutes to the VD clinic for a physical check-up every week, and for HIV

and syphilis blood tests every three months.52 These escort females to have more opportunity

to detect the disease earlier than males.



5.3 Marital status

     Unlike other studies,13-19 this study did evaluate marital status, which is an important

demographic factor, in order to determine the target population for program intervention and
34                                                                                 C. Netima


related policies regarding HIV in young people. Our findings in young people suggested that

people who are single are associated with late diagnosis. This could perhaps be explained by

the higher opportunity of having multiple partners in singles. In addition, people getting

married and pregnant women are encouraged to receive an HIV screening test.



5.4 Residence

       There were also geographic variations among late presenters in Thailand. We found

that the cases of reported HIV were highest in central Thailand (29.2%) and northern

Thailand (26.4%). However, late presenters were more likely to come from the central region

of Thailand (OR 2.40, p< 0.001 compared to the northern region). Furthermore, while the

prevalence of HIV in northern Thailand was two times higher, southern region had significant

higher proportion of late diagnosis of HIV in comparison to the northern region (OR 2.46, p<

0.001). Although sex trades and substance use are mostly centered around the larger cities,53,
54
     such as in Bangkok, Chiang Rai, Chiang Mai, and Phuket, northern Thailand sees more of

the NGO and Government intervention programs than does Bangkok,55, 56 and the southern

region like Phuket.54 Additionally, most UNICEF activities related to HIV/AIDS take place

in the upper north and the northeast, with project support from the UNICEF area offices in

Chiang Mai and Khon Kaen.57 Another non-governmental organization program is the Thai

Youth AIDS Prevention Project (TYAP). TYAP was created in 1995 to help in preventing

HIV/AIDS in young people and increase youth involvement in prevention activities in

                                            s
northern Thailand. Based in Chiang Mai, TYAP' principal goal is to create opportunities for

young people to develop the skills and power to diminish the impact of HIV/AIDS in

northern Thailand.58 These programs provide awareness and education that might help

explain the lower prevalence of late diagnosis. Furthermore, both government and non-

government sponsored works in northern Thailand have been instrumental in discouraging
The Invisible Epidemic: Factors associated with the Late Diagnosis in Thai Youth             35


young women from entering the sex trade and in developing HIV/AIDS awareness.59 These

programs might have an effect on people’s perception and awareness of HIV infection which

are better than in the central region. In southern Thailand, there are many issues regarding the

political situation and cultural factors60, which might be barriers in access to health care

service. Moreover, a research in southern Thailand showed the highest percentage of IDUs.61

These reasons might help to explain that late diagnosis was found to be higher than in the

northern region.

     On the other hand, within the provinces, rural areas were much more significantly

associated with late diagnosis (OR 1.15, p= 0.02). As the evidence in the Partner Relations

Survey, Thais in rural area were less likely to use condoms regularly. It was found that about

30% of both urban and rural married men reported consistent use, while urban single men

were twice as likely as their rural counterparts to use condoms consistently (48% versus

26%).62 In addition, a study in a rural community of Thailand showed that less than 50%Thai

adolescents in that area had good knowledge on HIV. Although all subjects knew that having

unsafe sex with a person infected with HIV could transmit HIV, but false knowledge to other

topics could be demonstrated.63 This highlights the important finding that there might be a

geographical disparity in the awareness of HIV/AIDS within the country. Furthermore,

the problem is not confined to only those areas with high HIV prevalence, but also the areas

that have low prevalence of HIV. This study therefore identifies that opportunities may exist

for NGO and government awareness programs in areas of low prevalence of HIV, due to the

higher proportion of late diagnosis.



5.5 Injecting drug users

     Our analysis on risk factors of HIV infection differed from previous Italian16 and

Swedish18 studies, which had found that IDU had significantly earlier diagnosis of HIV
36                                                                                 C. Netima


then other risk factors. This study found that IDU was a significant risk factor for late

diagnosis in univariate analysis but not multivariate analysis. However, IDU is likely to be a

substantial factor as there is evidence of increased incidence of HIV among IDUs.64 This has

prompted both concern and action on the part of the Thai government, such as needle

exchange programs65 and methadone maintenance programs.66

     Unlike adults, late diagnosis was high in young IDUs. Previous research showed that

young injectors think and behave differently from older IDUs.67 They are also treated

differently within their communities. Specifically, young IDUs have less knowledge about

HIV/AIDS, have a lower perception of their risk of acquiring HIV through either drug

injecting or sex, and are less likely to be identified as being an IDU than older IDUs.67

Additionally, in general, youth have a heightened risk of HIV infection as a result of many

factors, including risky sexual behaviors, substance abuse (including injecting drug use), and

lack of access to HIV information and preventive services. As a result, the utilization of

hospital and health care services might be low in IDUs in young people. As a consequence,

AIDS were diagnosed by the time of HIV diagnosis. Overall, this is still a critical target

group in the control of the transmission of HIV.



5.6 Sexual orientation

     Contrary to other studies,34,   35
                                          this study found that sexual orientation had no

association with late diagnosis in young patients. However, the cultural context needs to be

taken into consideration in order to interpret the result. The social acceptability and peer

pressure have an important effect on young people’s behaviors and decision-making.68

Accordingly, disclosing the fact that they are homosexual or bisexual is extremely

complicated for young Thai people. Stigma and prejudice might prevent some youths from

admitting their sexual behavior. Given this is such a sensitive subject for all youth, and that
The Invisible Epidemic: Factors associated with the Late Diagnosis in Thai Youth                                     37


homosexuality or bisexuality are not widely accepted in Thai culture,54 it is challenging to

health care personnel to obtain the facts. Subsequently, misclassification of sexual orientation

risk exposure should be taken into account.



5.7 Occupation

      Another key factor of late diagnosis is occupation, which can help to indicate specific

target groups for program intervention. Nonetheless, most previous studies did not include

occupation as a risk factor.13-19 We found that late diagnosis was higher in those who work as

a male/female bar worker, office worker, prisoner and people who had no job.

      For male/female bar worker, our findings showed that approximately two-thirds of bar

workers with HIV infection were late diagnosis. This might be associated with poor

education. People working as pub workers tend to have lower education levels.69 The data

from 2005 HIV Sentinel Behavior-Surveillance among bar workers in Thailand revealed that

male bar workers were mostly graduated from lower secondary school (24.4%) and upper

secondary school (24.1%), while female bar workers were mostly graduated from primary

school (23.6%), lower secondary school (20.9%), and upper secondary school (19.8%).69 In

addition, the data also reported increased sexual activities and decreased condom use among

male bar workers with female sex workers. This high risk behavior may be linked to a lack

of knowledge or education in regards to HIV/AIDS. Of the Bar workers tested, only 54.1%

of male and 56.2% of female correctly answered the questions regarding HIV/AIDS

knowledge according to UNGASS indicators † .69 Furthermore, one report found increased


†
  In 2002 the UNAIDS Secretariat collaborated with UNAIDS Cosponsors and other partners to develop a series of core
indicators to measure progress in implementing the Declaration of Commitment. In 2005, the new version of indicators that
differentiated between forms of the epidemic (concentrated or generalized) was disseminated. One of the UNGASS
indicators regarding the knowledge and behavior is constructed from responses to the following set of prompted questions:
1. Can having sex with only one faithful, uninfected partner reduce the risk of HIV transmission?
2. Can using condoms reduce the risk of HIV transmission?
3. Can a healthy-looking person have HIV?
4. Can a person get HIV from mosquito bites?
5. Can a person get HIV by sharing a meal with someone who is infected?
38                                                                                   C. Netima


drug and substance use in this population. This contributed to risky behavior, for example,

the needle sharing in injecting drugs. Therefore, male and female bar workers need to be

educated, receive the right information related to HIV disease and perceive the risk of

infection.

     For office workers, the reason of late diagnosis might be explained by the fact that the

there are high proportion of people who are unaware of disease among this group. This group

was not identified as a high risk group of HIV. Thus, there is limited research on HIV risk

behaviors among Thai office workers. However, one study in 1996 showed that less than

20% of office workers used condom consistently with commercial sex workers.62

     As for prisoners, the rate of HIV infection is higher than that in the general population.

Our study found 96.6% of prisoners were diagnosed late. Even though each of the prisons has

an ambulatory medical unit that provides inmates with medical care, including HIV testing,

treatment and counseling, the HIV tests can be given only if a prisoner voluntarily requests

one. The test requests are rare, and usually made when an inmate discovers a lesion or

become symptomatic.70 Moreover, the staffs are limited in their ability to provide health

teams and especially the counseling services needed to accompany HIV testing.70

Accordingly, early HIV testing is rare.

     Finally, unemployment can lead to behavior that directly exposes young people to HIV

and other sexually transmitted infections. There are several ways in which youth

unemployment increases risk of HIV infection. Many young men and women around the

world are compelled into early sexual activity to earn money.71 Our study found that

unemployment was associated with late diagnosis of HIV, a finding consistent with a US

study.48 This could come from many reasons, but there are several possibilities that do stand

out. One is the barriers that poverty causes in the access to heath care. Yet another possibility

is that patients cannot report what their job is, as it is illegal. This too would present
The Invisible Epidemic: Factors associated with the Late Diagnosis in Thai Youth             39


difficulties in obtaining health services. Poor access to care leads to delayed diagnosis of HIV.

The other possibility is the expected number of mentally disturbed among this group. There is

emerging research that poverty and unemployment can create a social context that negatively

impacts the psychosocial state of young people.72 A sense of powerlessness, lack of self-

identity, lack of purpose and optimism can lead young people to engage in behaviors that

increase their risk of HIV and other illnesses.72 As a result, these would diminish the capacity

to make good health decisions.



5.8 Health care services

     Health care service is another important factor regarding late diagnosis of HIV. IPD

patients and patients who received treatments from BMA (Bangkok Metropolitan

Administration) hospital, university hospital, regional/general hospitals, and health

services under the Department of Disease Control were associated with late diagnosis,

more than those who received treatment from community hospitals. However, the Thailand

National Institute of Health (NIH) established an external quality assessment (EQA) scheme

on HIV serology testing in 1994. The recent research on the evaluation of HIV serology

testing during 2000- 2006 period showed that, there were no significant differences in the

number of errors found between government hospital laboratories, private hospital and clinic

laboratories and blood screening laboratory centers.73 Thus, the high proportion of late

diagnosis of HIV might be explained by the fact that accessibility to the Thai primary health

care system has been improving continuously. The evidence showed that there is increased

utilization of primary care services, and community hospitals.74 Moreover, patients who have

severe disease will be referred to a higher level of care. Thus, the result of late diagnosis of

HIV in those BMA, university and regional/general hospital is not surprising.
40                                                                                 C. Netima


5.9 AIDS-defining illnesses

     Our study showed that Mycobacterium tuberculosis, Pneumocystis carinii pneumonia,

wasting syndrome, Cryptococcosis and esophageal candidiasis were more frequently

diagnosed as an AIDS-defining illness in patients with late diagnosis. These findings were

similar to a study in Spain.17 Our findings also showed that multiple AIDS-defining illnesses

were associated with late diagnosis. Patients with multiple diseases tended to be diagnosed

late. However, these opportunistic infections suggest the presence of low CD4 count, and are

expected in late presenters. For example, among patients with oral candidiasis and

                                                                 s
tuberculosis, CD4 count ranges between 250 and 500/µL; for Kaposi' sarcoma, lymphoma,

and cryptosporidiosis, CD4 count ranges between 150 and 200/µL; for Pneumocystis carinii

pneumonia, disseminated Mycobacterium avium complex, herpes simplex ulceration,

toxoplasmosis, cryptococcosis, and esophageal candidiasis, CD4 count ranges between 75

and 125/µL; and for cytomegalovirus retinitis, CD4 count is less than 50/µL.75 A previous

research confirmed the better outcome of Pneumocystis carinii pneumonia when it’s

diagnosed early.76 Often patients died because of opportunistic infections rather than HIV

itself. Comprehensive prevention, treatment, and suppression of opportunistic infections have

improved both the quality and years of life of people living with AIDS.



5.10 Policy implication

     It is important to improve the policies regarding the early detection of HIV/AIDS. From

the macroeconomic point of view, the total health expenditure on HIV/AIDS increased from

2,996 million Baht in 2000 (US$ 74.4 million) to 4,188 million Baht in 2003 (US$ 101.3

million). Of these, antiretroviral therapy and treatment of opportunistic infections accounted

for 85.1% of total AIDS spending.77 Early detection of HIV would reduce the therapeutic cost

of opportunistic infections and other related costs. A study found that initiation of HAART at
The Invisible Epidemic: Factors associated with the Late Diagnosis in Thai Youth                 41


a CD4+ T-cell count greater than 350 cells/ might be cost-effective (less than $50,000 per

quality-adjusted life-year) and might result in longer quality-adjusted survival compared with

initiating HAART at a CD4+ T-cell count between 200 and 350 cells/µL.78 Furthermore,

from the public health point of view, early detection would benefit in terms of a decrease in

the disease transmission.

     Our study can be applied to future policy planning regarding AIDS education, screening,

diagnosis or treatment in Thailand, as follows:



1) AID education and prevention

      This study showed that there exist possible gains in improving the HIV/AIDS education

in the Thai education system. As the study showed most young people were diagnosed late,

supplementing the evidence from other research, which found HIV/AIDS knowledge in some

specific groups is still low. Thus, in order to improve the awareness of disease in young

people and encourage the early detection, HIV/AIDS knowledge should be integrated in the

education system. However, for those populations outside the Thai education system, other

strategies need to be applied. Encouraging and supporting NGOs and CBOs (community-

based organization) intervention is one way to reach the late diagnosis groups, such as people

who live in rural areas and IDUs. In addition, HIV/AIDS intervention should be extended to

not only highest risk of HIV infection groups, but also bar workers, prisoners, unemployed

and office workers who were found to have a higher incidence of late diagnosis. In the mean

time, it is important to encourage those people at risk of late diagnosis to have an HIV test.



2) Diagnosis of HIV/AIDS

      HIV voluntary counseling and testing (VCT) in Thailand are now available at

approximately 1,000 hospitals and clinics across the country, however, the shortage of staff is
 42                                                                                 C. Netima


 still a problem in Thailand that needs to be overcome.77 There is also inadequate number of

 counselors to provide service in every health care setting responsible for HIV/AIDS, TB, and

 STI care. The counselors are important in terms of providing important information to

 HIV/AIDS patients and encouraging HIV testing. Thus, it is necessary that VCT services be

 strengthened through capacity building and support. Moreover, emphasizing free and

 anonymous access to HIV testing might help increase the utilization. VCT should be

 promoted as a service for the general population, especially young people. Public education

 and increased test utilization is not the complete answer, emphasizing to health care

 professionals the importance of recognition of the symptoms of HIV is significant to early

 detection of the disease.



3) Treatment of HIV/AIDS

      Our study showed that patients who received treatments from BMA hospital, university

 hospital and regional/general hospitals were associated with late diagnosis, more than those

 who received treatment from community hospitals. Thus, HIV/AIDS care and treatment

 should be integrated into the primary health care infrastructure, so it can reach people living

 with HIV in their community and help to relieve the burden of tertiary care.



 5. 10 Study limitations

      In interpreting the results of this study, possible limits and biases should be discussed.

 Firstly, misclassification bias could occur because of the definition of late diagnosis of HIV.

 We defined “late diagnosis” by using the duration from diagnosis of HIV until the diagnosis

 of AIDS. Less than 6 months was defined as “late diagnosis.” There is no precise cutoff point

 between late or early diagnosis. However, to confirm the consistency of the study results, we

 changed the definition to 2, 3 and 12 months. The findings were consistent to those using the
The Invisible Epidemic: Factors associated with the Late Diagnosis in Thai Youth                43


6-month definition and bias from this source was therefore unlikely to occur. Secondly, there

are some known factors that influence the rate of HIV disease progression. For instance,

psychosocial factor such as weekly use of cocaine and hallucinogens is associated with faster

progression.   Genetic    susceptibility,   acquired    immunity,     nutritional   state/wellness,

pharmacologic characteristics, drug susceptibility, gene mutation and viral fitness are also

potential risk factors.79 Although these factors may be related to the disease progression of

HIV, they are not associated with the existing risk factors. Therefore, they will not confound

the findings of our population-based study. Finally, although our data represent all of the

HIV/AIDS diagnoses reported in Thailand from 1997 through 2006, underreporting couldn’t

be excluded. However, underreporting was likely to be a random process and studying a

random subset of the general population would not affect the findings. Moreover, it seems

reasonable to assume that such underreporting would be equally distributed among late and

non-late diagnosis patients and among specific groups, and would not bias the findings.



5.11 Conclusion

     In conclusion, we have identified and described the factors associated with late

diagnosis of HIV, specifically in young Thai people aged 15-24 years old. This study is

beneficial in terms of policy planning for Thai youth, a group that has been recognized as

having a high vulnerability to HIV infection. The generalizability of the study finding is high

since it is a population-based study. Overall, the results of this study may suggest changes

and improvements to the screening tests, prevention policies, and education programs for the

right target populations. As a result, it will eventually help decrease the incidence of HIV

infection. Further research regarding the specific reasons of late diagnosis, the evaluation of

income and education level need to done in order to help improve the overall HIV situation in

Thailand.
44                                                                                C. Netima


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The Invisible Epidemic: Factors associated with the Late Diagnosis in Thai Youth                 49


Table 1. The definitions of late and non-late diagnosis of HIV infection

        Study Population                     Late diagnosis               Non-late diagnosis
Patients aged 15-24 years old,
excluding:                            1. A first HIV positive test
   - perinatally infected patients.   within 6 months of AIDS
   - patients who were reported                                             Rest of the group.
                                      diagnosis.
      as HIV positive, without
      developing AIDS, within         2. Death occurred within 6
      the last 6 months of the        months of HIV diagnosis
      study period
50                                                                                     C. Netima




Table 2. Main data set variables

 No.     Variables       Type                                 Definition

  1     SCODE           Number     ID
  2     AGE              Text      Age
  3     BEHAVE           Text      Sexual orientation
  4     BLDCAUSE         Text      Reason for blood transfusion
  5     BLDYEAR        Date/Time   Date of Blood transfusion (HIV positive)
  6     CD4              Text      Number of CD 4 count
  7     DDEAD          Date/Time   Date of death
  8     DDIAGB         Date/Time   Date of first AIDS illness
  9     DDIAGE         Date/Time   Date of AIDS treatment
  10    DIAGB            Text      First diagnosis
  11    DIAGE            Text      Definite diagnosis
  12    DREPORT        Date/Time   Date of case report
  13    HIVDIAGB       Date/Time   Date of first HIV illness
  14    HIVDIAGE       Date/Time   Date of HIV treatment
  15    INSTITUTE        Text      Type of health care service
  16    MARRY            Text      Marital status
  17    METRO            Text      Residence
  18    OCCF             Text              s
                                   Father' occupation
  19    OCCM             Text               s
                                   Mother' occupation
  20    OCCNEW           Text      Current occupation
  21    OCCOLD           Text      Previous occupation
  22    PROVINCE         Text      Province
  23    RACE             Text      Race
  24    RISK             Text      Risk factor
  25    RSTATUS          Text               s
                                   Patient' status
  26    SCREENT          Text      Screening test
  27    SEX              Text      Gender
  28    SUPPLET          Text      Supplementary test
  29    SYMPTOM1        Yes/No     Oral candidiasis or hairy leukoplakia
  30    SYMPTOM10       Yes/No     Persistent cough or any pneumonia more than 2 month (except TB)
                                   Lymphadenopathy more than 1 cm. At least 2 noninguinal sites for
        SYMPTOM11       Yes/No
  31                               more than 1 month
The Invisible Epidemic: Factors associated with the Late Diagnosis in Thai Youth                        51


  32     SYMPTOM12         Yes/No      Other
  33     SYMPTOM2          Yes/No      Herpes Zoster (more than 1 dermatome)
  34     SYMPTOM3          Yes/No      Central nervous system dysfunction
  35     SYMPTOM4          Yes/No      Diarrhea for more than 1 month
  36     SYMPTOM5          Yes/No      Fever for more than 1 month
  37     SYMPTOM6          Yes/No      Cachexia or more than 10% weigh loss
  38     SYMPTOM7          Yes/No      Asthenia more than 1 month
  39     SYMPTOM8          Yes/No      Persistent dermatitis (more than 1 month)
  40     SYMPTOM9          Yes/No      Anemia, Lymphopenia thrombocytopenia
  41     TCELL              Text       T cell test
  42     TYPE                Text      Type of patient



Table 2. Main data set variables (continued)

   No.       Variables              Type                                Definition

   43      TYPE1_1                  Yes/No         Candidiasis
   44      TYPE1_10                 Yes/No         Histoplasmosis
   45      TYPE1_11                 Yes/No         Isosporiasis
   46      TYPE1_12                 Yes/No                 s
                                                   Kaposi' sarcoma
   47      TYPE1_13                 Yes/No         Lymphoma, Burkitt'   s
   48      TYPE1_14                 Yes/No         Lymphoma, immunoblastic
   49      TYPE1_15                 Yes/No         Lymphoma, primary in brain
   50      TYPE1_16                 Yes/No         Mycobacterium avium complex
   51      TYPE1_17                 Yes/No         Mycobacterium
   52      TYPE1_18                 Yes/No         Mycobacterium Tuberculosis
   53      TYPE1_181                Yes/No         Pulmonary Tuberculosis
   54      TYPE1_182                Yes/No         Extrapulmonary Tuberculosis
   55      TYPE1_19                 Yes/No         Pneumonia recurrent (>1 time in a year)
   56      TYPE1_2                  Yes/No         Invasive cervical cancer
   57      TYPE1_20                 Yes/No         Pneumocystis carinii
   58      TYPE1_21                 Yes/No         Penicillium marneffei
   59      TYPE1_22                 Yes/No         Progressive multifocal leukonephalopathy
   60      TYPE1_23                 Yes/No         Salmonella Septicemia
   61      TYPE1_24                 Yes/No         Toxoplasmosis
   62      TYPE1_25                 Yes/No         Wasting syndrome
   63      TYPE1_26                 Yes/No         Nocardiosis
   64      TYPE1_28                 Yes/No         Rhodococcosis
   65      TYPE1_29                 Yes/No         Serious bacterial infection, recurrent or multiple
   66      TYPE1_3                  Yes/No         Coccidiodomycosis
   67      TYPE1_4                  Yes/No         Cryptococcosis
   68      TYPE1_5                  Yes/No         Cryptosporidiosis
   69      TYPE1_6                  Yes/No         Cytomegalovirus
   70      TYPE1_7                  Yes/No         Cytomegalovirus retinitis
   71      TYPE1_8                  Yes/No         HIV encephalopathy
   72      TYPE1_9                  Yes/No         Herpes simplex >1 month
   73      TYPE2                    Yes/No         AIDS category 2 (CD 4 < 200/µL 2 times)
52                                                                                C. Netima


     74   TYPE3_M            Yes/No       Major signs for pediatric AIDS diagnosis
     75   TYPE3_M1           Yes/No       Weight loss or failure to thrive
     76   TYPE3_M2           Yes/No       Chronic/recurrent diarrhea more than 1 month
     77   TYPE3_M3           Yes/No       Chronic/recurrent fever more than 1 month
     78   TYPE3_M4           Yes/No       Persistent or severe lower respiratory tract
     79   TYPE3_N            Yes/No       Minor signs for pediatric AIDS diagnosis
     80   TYPE3_N1           Yes/No       Generalized lymphadenopathy
     81   TYPE3_N2           Yes/No       Oral thrush
     82   TYPE3_N3           Yes/No       Repeated common infections
     83   TYPE3_N4           Yes/No       Chronic cough
     84   TYPE3_N5           Yes/No       generalized dermatitis
     85   TYPE3_N6           Yes/No       Confirmed maternal or children HIV infection
     86   YMD                 Text        Age by year , month or day
Table 3. Sociodemographic Characteristics of 15-24 years old persons with HIV/AIDS -
population based study, Thailand, 1 January 1997- 30 June 2006
           Characteristics                                   n             (%)
 Gender
    Male                                                      11,370             (48.0)
    Female                                                    12,323             (52.0)
 Age group
    15-16                                                      268                (1.1)
    17-18                                                      827                (3.5)
    19-20                                                     2,787              (11.8)
    21-22                                                     6,681              (28.2)
    23-24                                                     13,130             (55.4)
 Marital Status
    Single                                                    11,011             (46.5)
    Married                                                   10,703             (45.2)
    Separated                                                  357                (1.5)
    Widow                                                      892                (3.8)
    Divorce                                                    506                (2.1)
    Unknown                                                    224                (0.9)
 Race
    Thai                                                      23,138             (97.6)
    Other                                                      327                (1.4)
    Unknown                                                    228                (1.0)
 Occupation
    Laborer                                                   11,771             (49.7)
    Farmer                                                    4,408              (18.6)
    Civil servant                                              289                (1.2)
    Business owner                                              19                (0.1)
    Merchant                                                   708                (3.0)
    Student                                                    649                (2.7)
    Office worker                                              213                (0.9)
    Sex worker                                                 136                (0.6)
    Male/female bar worker                                      65                (0.3)
    Housewife                                                 1,760               (7.4)
    Prisoner                                                   439                (1.9)
    Unemployment                                              1,779               (7.5)
    Other                                                     1,457               (6.1)
The Invisible Epidemic: Factors associated with the Late Diagnosis in Thai Youth            53


  Region
     Central Region                                                  6,917         (29.2)
     Eastern Region                                                  2,403         (10.2)
     Northeastern Region                                             5,025         (21.2)
     Northern Region                                                 6,261         (26.4)
     Southern Region                                                 3,087         (13.0)
  Residence
     Metropolis                                                     3,284          (13.9)
     Suburban                                                       2,324           (9.8)
     Rural                                                          14,297         (60.3)
     Unknown                                                        3,788          (16.0)
54                                                                         C. Netima


Table 4. Risk factors and health information of 15-24 years old persons with HIV/AIDS
- population based study, Thailand, 1 January 1997- 30 June 2006 (n = 23,693)
Characteristics                                                 n           (%)


Definite Diagnosis
    AIDS                                                      18,206       (76.9)
    Symptomatic HIV                                            5,482       (23.1)
    Asymptomatic HIV                                             5          (0.0)
Patient's status
    Alive                                                     18,458       (77.9)
    Living abroad                                                8          (0.0)
    Dead                                                       5,226       (22.1)
    Unknown                                                      1          (0.0)
Treatment Center
    Community hospitals*                                       7,264       (30.7)
    Regional/General hospitals*                               10,046       (42.4)
    University hospitals                                        800         (3.4)
    Bangkok Metropolitan Administration (BMA) hospitals        1,621        (6.8)
    Private hospitals/Clinics                                   703         (3.0)
    Health services under Department of Disease Control        1,357        (5.7)
    Other†                                                     1,541        (6.5)
    Unknown                                                     361         (1.5)
Type of patient
    OPD§                                                       7,817       (33.0)
    IPD¶                                                      15,855       (66.9)
    Unknown                                                     21          (0.1)
Sexual orientation
    Heterosexual                                              20,546       (86.7)
    Homosexual                                                  225         (1.0)
    Bisexual                                                    69          (0.3)
    Unknown                                                    2,853       (12.0)
Risk factor
    IDUs**                                                     1,353        (5.7)
    Sexual transmission                                       20,575       (86.8)
    Other                                                       21          (0.1)
    Unknown                                                    1,744        (7.4)
AIDS-defining illness
    Mycobacterium tuberculosis                                 5,478       (23.1)
    Pneumocystis carinii pneumonia                             4,368       (18.4)
    Wasting syndrome                                           3,974       (16.8)
    Cryptococcocis                                             2,792       (11.8)
    Oesophageal candidiasis                                     895         (7.4)
Year of HIV/AIDS diagnosis
    1997-1999                                                 11,854       (50.0)
    2000-2002                                                  7,523       (31.8)
    2003-2005                                                  4,316       (18.2)
*
   Not including hospitals in Bangkok.
§
    Out Patient Department
¶
    Inpatient Department
**
   Injecting Drug Users
The Invisible Epidemic: Factors associated with the Late Diagnosis in Thai Youth            55


Table 5. Proportion of late diagnosis and non-late diagnosis* of HIV infection in young
patients aged 15-24 years old-- Population based study, Thailand, 1 January 1997- 30
June 2006.
                                                  Late diagnosis
                                                  20.528 (86.6%)
 Characteristics                    Total        No.           (%)             p-value†
 Gender                                                                            <0.001
      Male                              11,370        10,070           (88.6)        --
      Female                            12,323        10,458           (84.9)        --
 Age group                                                                         <0.001
      15-16                               268           219            (81.7)        --
      17-18                               827           698            (84.4)        --
      19-20                              2,787         2,332           (83.7)        --
      21-22                              6,681         5,798           (86.8)        --
      23-24                             13,130        11,481           (87.4)        --
 Marital Status                                                                    <0.001
      Single                            11,011         9,790           (88.9)        --
      Married                           10,703         9,059           (84.6)        --
      Separated                          357            320            (89.6)        --
      Widow                              892            746            (83.6)        --
      Divorce                            506            426            (84.2)        --
      Unknown                            224            187            (83.5)        --
 Race                                                                               0.22
      Thai                              23,138        20,049           (86.6)        --
      Other                              327           289             (88.4)        --
      Unknown                            228           190             (83.3)        --
 Occupation                                                                        <0.001
      Laborer                           11,771        10,159           (86.3)        --
      Farmer                             4,408         3,674           (83.3)        --
      Civil servant                       289           249            (86.2)        --
      Business owner                      19            16             (84.2)        --
      Merchant                            708           617            (87.1)        --
      Student                             649           577            (88.9)        --
      Office worker                       213           203            (95.3)        --
      Sex worker                          136           116            (85.3)        --
      Male/female bar worker              65            63             (96.9)        --
      Housewife                          1,760         1,558           (88.5)        --
      Prisoner                            439           424            (96.6)        --
      Unemployment                       1,779         1,626           (91.4)        --
      Other                              1,457         1,246           (85.5)        --
 Region                                                                            <0.001
      Central region                     6,917         6,391           (92.4)        --
      Eastern region                     2,403         1,945           (80.9)        --
      Northeastern region                5,025         4,202           (83.6)        --
      Northern region                    6,261         5,177           (82.7)        --
      Southern region                    3,087         2,813           (91.1)        --
 Residence                                                                         <0.001
      Rural                             14,297        12,157           (85.0)        --
      Suburban                           2,324         2,030           (87.3)        --
      Metropolis                         3,284         2,860           (87.1)        --
      Unknown                            3,788         3,481           (91.9)        --
56                                                                                                C. Netima


Table 5. Proportion of late diagnosis and non-late diagnosis* of HIV infection in young
patients aged 15-24 years old-- Population based study, Thailand, 1 January 1997- 30
June 2006 (continued).
                                                    Late diagnosis
                                                    20.528 (86.6%)
 Characteristics                    Total      No.               (%)             p-value†
 Year of HIV/AIDS diagnosis                                                                            <0.001
      1997-1999                              11,854        10,045                (84.7)                   --
      2000-2002                               7,523         6,529                (86.8)                   --
      2003-2006                               4,316         3,954                (91.6)                   --
 Treatment center                                                                                      <0.001
      Community hospitals ¶                   7,264         5,848                (80.5)                   --
                                 ¶
      Regional/General hospitals             10,046         8,782                (87.4)                   --
      University hospitals                      800          729                 (91.1)                   --
       Bangkok Metropolitan
      Administration (BMA) hospitals          1,621         1,614                (99.6)                   --
      Private hospitals/Clinics                 703          590                 (83.9)                   --
      Health services under Department
      of Disease Control                      1,357         1,212                (89.3)                   --
      Other**                                 1,541         1,432                (92.9)                   --
      Unknown                                   361          321                 (88.9)                   --
 Type of patient                                                                                       <0.001
      OPD††                                   7,817         6,207                (79.4)                   --
      IPD§§                                  15,855        14,301                (90.2)                   --
      Unknown                                    21          20                  (95.2)                   --
 Sexual orientation                                                                                     0.48
      Heterosexual                           20,546        17,779                (86.5)                   --
      Homosexual                                225          200                 (88.9)                   --
      Bisexual                                   69          62                  (89.9)                   --
      Unknown                                 2,853         2,487                (87.2)                   --
 Risk factor                                                                                           <0.001
      IDUs ¶ ¶                                1,353         1,231                (91.0)                   --
      Sexual transmission                    20,575        17,752                (86.3)                   --
      Other                                      21          20                  (95.2)                   --
      Unknown                                 1,744         1,525                (87.4)                   --
 AIDS-defining illness                                                                                 <0.001
      Mycobacterium tuberculosis              5,478         5,469                (99.8)                   --
      Pneumocystis carinii pneumonia          4,368         4,363                (99.9)                   --
      Wasting syndrome                        3,974         3,967                (99.8)                   --
      Cryptococcocis                          2,792         2,785                (99.7)                   --
      Oesophageal candidiasis                   895          892                 (99.7)                   --
* Patients with late diagnosis of HIV were defined as persons who had their first HIV positive test ≤ 6 months
of diagnosis of AIDS; Patients with non-late diagnosis were defined as persons who had their first HIV positive
test > 6 months of diagnosis of AIDS
§ Confidence interval
¶ Not included hospitals in Bangkok
** Including hospitals under the Department of Correction, Department of Health, Department of Medical
Services, Ministry of Public Health, Ministry of Defence, Ministry of Inferior and other ministries, Provincial
Public Health Offices, Thai Red Cross, and State Enterprises
§§ Inpatient Department
¶ ¶ Injection drug users
The Invisible Epidemic: Factors associated with the Late Diagnosis in Thai Youth                              57


Table 6. Predictors of late diagnosis* of HIV in young patient aged 15-24 years old, both
unadjusted and adjusted odds ratios, Thailand, 1 January 1997- 30 June 2006
                                     Crude                                      Adjusted
Characteristics                    odds ratio      (95% CI†)         p-value   odds ratio     (95% CI†)       p-value
Gender
     Male                             1.38         (1.28-1.49)       <0.001       1.24        (1.13-1.36)     <0.001
     Female                         Referent                            --      Referent                         --
Age group
     15-16                          Referent                            --      Referent                         --
     17-18                            1.21         (0.84-1.74)        0.30        1.34        (0.91-1.98)       0.14
     19-20                            1.15         (0.83-1.59)        0.41        1.21        (0.85-1.72)       0.29
     21-22                            1.47         (1.07-2.02)        0.02        1.52        (1.07-2.14)       0.02
     23-24                            1.56         (1.14-2.13)        0.01        1.61        (1.14-2.26)       0.01
Marital Status
     Married                        Referent                            --      Referent                         --
     Single                           1.46         (1.34-1.58)       <0.001       1.18        (1.07-1.30)     <0.001
     Separated                        1.57         (1.11-2.21)        0.01        1.28        (0.89-1.84)       0.19
     Widow                            0.93         (0.77-1.12)        0.42        1.10        (0.91-1.35)       0.33
     Divorce                          0.97         (0.76-1.23)        0.78        1.08        (0.83-1.41)       0.55
     Unknown                          0.92         (0.64-1.31)        0.63        0.81        (0.55-1.19)       0.29
Race
     Thai                           Referent                            --         --              --            --
     Other                            1.17         (0.83-1.65)        0.36         --              --            --
     Unknown                          0.77         (0.54-1.09)        0.14         --              --            --
Occupation
     Laborer                        Referent                            --      Referent                         --
     Farmer                           0.79         (0.72-0.87)       <0.001       0.95        (0.85-1.06)       0.33
     Civil servant                    0.99         (0.70-1.38)        0.94        0.57        (0.40-0.83)      <0.01
     Business owner                   0.85         (0.25-2.91)        0.79        0.89        (0.25-3.19)       0.86
     Merchant                         1.08         (0.86-1.35)        0.53        1.07        (0.84-1.36)       0.60
     Student                          1.27         (0.99-1.63)        0.06        1.01        (0.77-1.32)       0.96
     Office worker                    3.22         (1.70-6.09)       <0.001       2.58        (1.33-5.00)       0.01
     Sex worker                       0.92         (0.57-1.48)        0.73        0.99        (0.59-1.65)       0.97
     Male/female bar worker           5.00        (1.22-20.45)        0.03        5.19       (1.25-21.53)       0.02
     Housewife                        1.22         (1.05-1.43)        0.01        1.12        (0.94-1.32)       0.20
     Prisoner                         4.49         (2.67-7.53)       <0.001       2.31        (1.35-3.96)      <0.01
     Unemployment                     1.69         (1.42-2.01)       <0.001       1.32        (1.10-1.58)      <0.01
     Other                            0.94         (0.80-1.09)        0.41        0.88        (0.74-1.04)       0.13
Region
     Northern Region                Referent                            --      Referent                         --
     Eastern Region                   0.89         (0.79-1.00)        0.06        1.12        (0.98-1.28)       0.08
     Northeastern Region              1.07         (0.97-1.18)        0.19        1.46        (1.31-1.63)     <0.001
     Central region                   2.54         (2.28-2.84)       <0.001       2.40        (2.12-2.73)     <0.001
     Southern Region                  2.15         (1.87-2.47)       <0.001       2.46        (2.11-2.86)     <0.001
Residence
     Metropolis                     Referent                            --      Referent                         --
     Suburban                         1.02         (0.87-1.20)        0.77        1.12        (0.94-1.33)       0.19
     Rural                            0.84         (0.75-0.94)       <0.001       1.15        (1.02-1.31)       0.02
     Unknown                          1.68         (1.44-1.96)       <0.001       1.55        (1.31-1.84)     <0.001
*
  Patients with late diagnosis of HIV were defined as persons who had their first HIV positive test ≤ 6 months of
diagnosis of AIDS; Patients with non-late diagnosis were defined as persons who had their first HIV positive
test
†
  Confidence interval.
Multivariate logistic models include : Gender, age group, marital status, occupation, region, residence,
treatment center, type of patient, sexual orientation, risk factor, numbers of AIDS-defining illnesses, and year of
HIV/AIDS diagnosis.
58                                                                                                  C. Netima


Table 6. Predictors of late diagnosis* of HIV in young patient aged 15-24 years old, both
unadjusted and adjusted odds ratios, Thailand, 1 January 1997- 30 June 2006
(continued)

                                     Crude                                p-      Adjusted                          p-
Characteristics                    odds ratio           (95% CI†)        value    odds ratio      (95% CI†)        value
Treatment Center
  Community hospitals§              Referent                              --        Referent                        --
                            §
  Regional/General hospitals          1.68              (1.55-1.83)     <0.001       1.46         (1.34-1.60)     <0.001
  University hospitals                2.49              (1.94-3.19)     <0.001       2.57         (1.97-3.37)     <0.001
  Bangkok Metropolitan
  Administration (BMA) hospitals     55.83            (26.51-117.56)    <0.001       57.51      (27.23-121.49)    <0.001
  Private hospitals/Clinics           1.26              (1.03-1.56)      0.03         0.72        (0.57-0.92)      0.01
  Health services under
  Department of Disease Control       2.02              (1.69-2.43)     <0.001        1.47        (1.20-1.80)     <0.001
  Other¶                              3.18              (2.60-3.90)     <0.001        2.26        (1.79-2.84)     <0.001
  Unknown                             1.94              (1.39-2.71)     <0.001        1.40        (0.95-2.06)      0.09
Type of patient
  OPD**                             Referent                              --        Referent                        --
      ††
  IPD                                 2.39               (2.21-2.58)    <0.001       2.30         (2.12-2.50)     <0.001
  Unknown                             5.19              (0.70-38.68)     0.11        2.47        (0.32-19.23)      0.39
Sexual orientation
  Heterosexual                      Referent                               --       Referent                         --
  Homosexual                          1.25              (0.82-1.89)       0.30       0.86         (0.55-1.34)       0.50
  Bisexual                            1.38              (0.63-3.01)       0.42       1.29         (0.57-2.94)       0.55
  Unknown                             1.06              (0.94-1.19)       0.35       0.82         (0.68-0.98)       0.03
Risk factor
  Sexual transmission               Referent                              --        Referent                         --
  IDUs§§                              1.60               (1.33-1.94)    <0.001       0.97         (0.78-1.20)       0.77
  Other                               3.18              (0.43-23.71)     0.26        2.94        (0.37-23.37)       0.31
  Unknown                             1.11               (0.96-1.28)     0.17        1.24         (1.00-1.54)       0.05
Numbers of AIDS-defining illnesses
  0-1                               Referent                              --        Referent                        --
  2                                  85.93            (35.70-206.81)    <0.001       86.36      (35.84-208.05)    <0.001
  3-7                                90.88            (12.77-646.62)    <0.001       92.06      (12.91-656.32)    <0.001
Year of HIV/AIDS diagnosis
    1997-1999                              Referent                          --      Referent                         --
    2000-2002                                1.18          (1.09-1.29)    <0.001       1.22         (1.12-1.34)     <0.001
    2003-2006                                1.97          (1.75-2.21)    <0.001       2.46         (2.16-2.81)     <0.001
*
  Patients with late diagnosis of HIV were defined as persons who had their first HIV positive test ≤ 6 months of
diagnosis of AIDS; Patients with non-late diagnosis were defined as persons who had their first HIV positive
test > 6 months of diagnosis of AIDS.
†
   Confidence interval.
§
   Not included hospitals in Bangkok.
¶
   Included hospitals under Department of correction, Department of Health, Department of Medical Services,
Ministry of Public Health, Ministry of Defence, Ministry of Inferior and other ministries, Provincial Public
Health Offices, Thai Red Cross, and State Enterprises.
**
   Outpatient Department.
††
   Inpatient Department.
§§
   Injecting drug users.
Multivariate logistic models include : Gender, age group, marital status, occupation, region, residence,
treatment center, type of patient, sexual orientation, risk factor, numbers of AIDS-defining illnesses, and year of
HIV/AIDS diagnosis.
The Invisible Epidemic: Factors associated with the Late Diagnosis in Thai Youth               59


Table 7. Number(s) of AIDS-defining illnesses in young patients with late diagnosis,
Thailand, January 1997 – June 2006
                                                                       Late diagnosis
   No. of AIDS-defining illness            Total                    No.                 (%)
                 0                        6,592                    3,458                16.8
                 1                        14,191                  14,166                69.0
                 2                        2,402                    2,397                11.7
                 >2                        508                      507                  2.5
   60                                                                                                       C. Netima


   Table 8. Predictors of late diagnosis of HIV in young patient aged 15-24 years old, both
   unadjusted and adjusted odds ratios, Thailand, 1 January 1997- 30 June 2006
   (Changing ‘late diagnosis’ definition to 2 months)
                          Late            Non-late
                     20,483(86.5%)     3,165 (13.5%)     Crude                                Adjusted
Characteristics       No.      (%)     No.       (%)    odds ratio   (95% CI†)      p-value   odds ratio   (95% CI†)      p-value
Gender
   Male              10,051   (49.1)   1,319   (41.1)    1.38        (1.28-1.49)    <0.001     1.25        (1.14-1.37)    <0.001
   Female            10,432   (50.9)   1,891   (58.9)   Referent                      --      Referent                      --
Age group
   15-16               219     (1.1)     49     (1.5)   Referent                      --      Referent                      --
   17-18               697     (3.4)    130     (4.0)    1.20        (0.84-1.72)     0.32      1.31        (0.89-1.94)     0.17
   19-20              2,328   (11.3)    459    (14.3)    1.13        (0.82-1.57)     0.45      1.17        (0.82-1.67)     0.38
   21-22              5,790   (28.3)    891    (27.8)    1.45        (1.06-2.00)     0.02      1.47        (1.04-2.07)     0.03
   23-24             11,449   (55.9)   1,681   (52.4)    1.52        (1.11-2.09)     0.01      1.54        (1.09-2.16)     0.01
Marital Status
   Married           9,040    (44.1)   1,663   (51.8)   Referent                      --      Referent                      --
   Single            9,767    (47.7)   1,244   (38.8)    1.44        (1.33-1.56)    <0.001     1.17        (1.06-1.29)    <0.01
   Separated          320      (1.6)     37     (1.1)    1.59        (1.13-2.24)     0.01      1.30        (0.90-1.88)     0.16
   Widow              744      (3.6)    148     (4.6)    0.92        (0.77-1.11)     0.40      1.10        (0.91-1.34)     0.33
   Divorce            426      (2.1)     80     (2.5)    0.98        (0.77-1.25)     0.87      1.10        (0.85-1.43)     0.47
   Unknown            186      (0.9)     38     (1.2)    0.90        (0.63-1.28)     0.56      0.80        (0.55-1.18)     0.26
Race
   Thai              20,004   (97.7)   3,134   (97.6)   Referent                      --          --            --          --
   Other              289      (1.4)     38     (1.2)    1.19        (0.85-1.67)     0.31         --            --          --
   Unknown            190      (0.9)     38     (1.2)    0.78        (0.55-1.11)     0.17         --            --          --
Occupation
   Laborer           10,149   (49.5)   1,622   (50.5)   Referent                      --      Referent                      --
   Farmer             3,657   (17.9)    751    (23.4)    0.78        (0.71-0.86)    <0.001     0.93        (0.83-1.03)     0.16
   Civil servant       248     (1.2)     41     (1.3)    0.97        (0.69-1.35)     0.84      0.56        (0.39-0.81)    <0.01
   Business owner       16     (0.1)      3     (0.1)    0.85        (0.25-2.93)     0.80      0.88        (0.25-3.17)     0.85
   Merchant            617     (3.0)     91     (2.8)    1.08        (0.86-1.36)     0.49      1.08        (0.85-1.37)     0.55
   Student             575     (2.8)     74     (2.3)    1.24        (0.97-1.59)     0.09      0.98        (0.75-1.28)     0.89
   Office worker       202     (1.0)     11     (0.3)    2.93        (1.60-5.40)    <0.001     2.33        (1.23-4.38)     0.01
   Sex worker          116     (0.5)     20     (0.6)    0.93        (0.58-1.49)     0.76      1.00        (0.60-1.67)     1.00
   Male/female bar
   worker              63     (0.3)     2      (0.1)      5.03       (1.23-20.59)    0.02       5.22       (1.26-21.65)    0.02
   Housewife         1,556    (7.6)    204     (6.4)      1.22        (1.04-1.42)    0.01       1.11        (0.93-1.31)    0.24
   Prisoner           424     (2.1)    15      (0.5)      4.52        (2.69-7.58)   <0.001      2.31        (1.35-3.95)   <0.01
   Unemployment      1,619    (7.9)    160     (5.0)      1.62        (1.36-1.92)   <0.001      1.25        (1.05-1.50)    0.01
   Other             1,241    (6.1)    216     (6.7)      0.92        (0.79-1.07)    0.28       0.86        (0.73-1.02)    0.07
Region
   Northern Region   5,149    (25.1)   1,112   (34.6)   Referent                      --      Referent                      --
   Eastern Region    1,942     (9.5)    461    (14.4)    0.91        (0.81-1.03)     0.12      1.15        (1.01-1.31)     0.04
   Northeastern
   Region            4,193    (20.5)   832     (25.9)     1.09       (0.99-1.20)     0.09       1.51       (1.36-1.69)    <0.001
   Central region    6,388    (31.2)   529     (16.5)     2.61       (2.34-2.91)    <0.001      2.47       (2.18-2.80)    <0.001
   Southern Region   2,811    (13.7)   276      (8.6)     2.20       (1.91-2.53)    <0.001      2.51       (2.16-2.92)    <0.001
Residence
   Metropolis         2,857   (14.0)    427    (13.3)   Referent                      --      Referent                      --
   Suburban           2,030    (9.9)    294     (9.1)    1.03        (0.88-1.21)     0.70      1.14        (0.96-1.35)     0.14
   Rural             12,128   (59.2)   2,169   (67.6)    0.84        (0.75-0.93)    <0.01      1.16        (1.02-1.31)     0.02
   Unknown            3,468   (16.9)    320    (10.0)    1.62        (1.39-1.89)    <0.001     1.53        (1.29-1.80)    <0.001
   *
     Patients with late diagnosis of HIV were defined as persons who had their first HIV positive test ≤ 2 months of
   diagnosis of
   AIDS; Patients with non-late diagnosis were defined as persons who had their first HIV positive test > 2 months
   of diagnosis of
   AIDS.
   †
     Confidence interval.
         The Invisible Epidemic: Factors associated with the Late Diagnosis in Thai Youth                                      61


         Table 8. Predictors of late diagnosis of HIV in young patient aged 15-24 years old, both
         unadjusted and adjusted odds ratios, Thailand, 1 January 1997- 30 June 2006
         (Changing ‘late diagnosis’ definition to 2 months; continued)
                                 Late            Non-late
                            20,483(86.5%)     3,165 (13.5%)
                                                                 Crude                                 Adjusted                       p-
Characteristics               No.    (%)      No.     (%)      odds ratio    (95% CI†)       p-value   odds ratio    (95% CI†)       value
Treatment Center
    Community hospitals§     5,829   (28.5)   1,435   (44.7)    Referent                       --       Referent                       --
    Regional/General
             §
    hospitals                8,773   (42.8)   1,273   (39.7)     1.70        (1.56-1.84)     <0.001      1.48        (1.35-1.62)     <0.001
    University hospitals      728     (3.5)     72     (2.3)     2.49        (1.94-3.19)     <0.001      2.57        (1.97-3.35)     <0.001
    Bangkok Metropolitan
    Administration (BMA)
    hospitals                1,614   (7.9)     7      (0.2)      56.76      (26.96-119.52)   <0.001      59.50      (28.17-125.68)   <0.001
    Private
    hospitals/Clinics         590    (2.9)    113     (3.5)      1.29        (1.04-1.58)      0.02       0.74        (0.59-0.94)      0.01
    Health services under
    Department of Disease
    Control                  1,212   (5.9)    145     (4.5)      2.06        (1.72-2.47)     <0.001      1.50        (1.22-1.83)     <0.001
    Other¶                   1,431   (7.0)    110     (3.4)      3.20        (2.62-3.92)     <0.001      2.27        (1.81-2.87)     <0.001
    Unknown                   306    (1.5)    55      (1.7)      1.37        (1.02-1.84)      0.04       0.97        (0.68-1.38)      0.85
Type of patient
    OPD**                    6,186   (30.2)   1,631   (50.8)    Referent                       --       Referent                       --
    IPD††                   14,277   (69.7)   1,578   (49.2)     2.39         (2.21-2.57)    <0.001      2.29         (2.10-2.48)    <0.001
    Unknown                    20     (0.1)     1      (0.0)     5.27        (0.71-39.32)     0.10       2.77        (0.36-21.46)     0.33
Sexual orientation
    Heterosexual            17,754   (86.7)   2,792   (87.0)    Referent                       --       Referent                       --
    Homosexual                199     (1.0)     26     (0.8)     1.20        (0.80-1.81)      0.38       0.83        (0.54-1.29)      0.41
    Bisexual                   62     (0.3)      7     (0.2)     1.39        (0.64-3.05)      0.41       1.30        (0.57-2.95)      0.54
    Unknown                  2,468   (12.0)    385    (12.0)     1.01        (0.90-1.13)      0.89       0.82        (0.68-0.99)      0.04
Risk factor
    Sexual transmission     17,712   (86.5)   2,863   (89.2)    Referent                       --       Referent                       --
    IDUs§§                   1,231    (6.0)    122     (3.8)     1.63         (1.35-1.97)    <0.001      0.98         (0.79-1.22)     0.88
    Other                      20     (0.1)     1      (0.0)     3.23        (0.43-24.10)     0.25       3.06        (0.39-24.27)     0.29
    Unknown                  1,520    (7.4)    224     (7.0)     1.10         (0.95-1.27)     0.21       1.22         (0.99-1.52)     0.07
Numbers of AIDS-defining illnesses
    0-1                     17,580   (85.8)   3,203   (99.8)    Referent                       --       Referent                       --
    2                        2,396   (11.7)     6      (0.2)     72.76      (32.63-162.25)   <0.001      73.36      (32.86-163.80)   <0.001
    3-7                       507     (2.5)     1      (0.0)     92.37      (12.98-657.27)   <0.001      93.87      (13.17-669.21)   <0.001
Year of HIV/AIDS diagnosis
    1997-1999               10,029   (49.0)   1,825   (56.9)    Referent                       --       Referent                       --
    2000-2002                6,521   (31.8)   1,002   (31.2)     1.18        (1.09-1.29)     <0.001      1.23        (1.12-1.34)     <0.001
    2003-2006                3,933   (19.2)    383    (11.9)     1.87        (1.66-2.10)     <0.001      2.41        (2.12-2.75)     <0.001
         *
           Patients with late diagnosis of HIV were defined as persons who had their first HIV positive test ≤ 2 months of
         diagnosis of AIDS; Patients with non-late diagnosis were defined as persons who had their first HIV positive
         test > 2 months of diagnosis of AIDS.
         †
            Confidence interval.
         §
            Not included hospitals in Bangkok.
         ¶
            Included hospitals under Department of correction, Department of Health, Department of Medical Services,
         Ministry of Public Health, Ministry of Defence, Ministry of Inferior and other ministries, Provincial Public
         Health Offices, Thai Red Cross, and State Enterprises.
         **
            Outpatient Department.
         ††
            Inpatient Department.
         §§
            Injecting drug users.
         Multivariate logistic models include : Gender, age group, marital status, occupation, region, residence,
         treatment center, type of patient, sexual orientation, risk factor, numbers of AIDS-defining illnesses, and year of
         HIV/AIDS diagnosis.
     62                                                                                                      C. Netima


     Table 9. Predictors of late diagnosis of HIV in young patient aged 15-24 years old, both
     unadjusted and adjusted odds ratios, Thailand, 1 January 1997- 30 June 2006
     (Changing ‘late diagnosis’ definition to 3 months)
                          Late            Non-late
                     20,483(86.5%)     3,165 (13.5%)     Crude                                Adjusted
Characteristics       No.      (%)      No.      (%)    odds ratio   (95% CI†)      p-value   odds ratio   (95% CI†)      p-value
Gender
   Male              10,059   (49.1)   1,311   (41.1)     1.38       (1.28-1.49)    <0.001      1.25       (1.13-1.37)    <0.001
   Female            10,441   (50.9)   1,882   (58.9)    Referent                     --       Referent                     --
Age group
   15-16              219      (1.1)     49     (1.5)    Referent                     --       Referent                     --
   17-18              697      (3.4)    130     (4.1)     1.20       (0.84-1.72)     0.32       1.32       (0.89-1.95)     0.16
   19-20             2,329    (11.4)    458    (14.3)     1.14       (0.82-1.58)     0.44       1.19       (0.83-1.69)     0.34
   21-22             5,794    (28.2)    887    (27.8)     1.46       (1.06-2.01)     0.02       1.49       (1.06-2.11)     0.02
   23-24             11,461   (55.9)   1,669   (52.3)     1.54       (1.12-2.10)     0.01       1.57       (1.11-2.21)     0.01
Marital Status
   Married           9,045    (44.1)   1,658   (51.9)    Referent                     --       Referent                     --
   Single            9,778    (47.7)   1,233   (38.6)     1.45       (1.34-1.57)    <0.001      1.18       (1.07-1.30)    <0.001
   Separated          320      (1.6)     37     (1.2)     1.59       (1.12-2.24)     0.01       1.29       (0.90-1.86)     0.17
   Widow              744      (3.6)    148     (4.6)     0.92       (0.77-1.11)     0.38       1.10       (0.90-1.34)     0.35
   Divorce            426      (2.1)     80     (2.5)     0.98       (0.76-1.25)     0.85       1.09       (0.84-1.42)     0.50
   Unknown            187      (0.9)     37     (1.2)     0.93       (0.65-1.32)     0.67       0.83       (0.56-1.22)     0.33
Race
   Thai              20,021   (97.7)   3,117   (97.6)    Referent                    0.23         --            --          --
   Other              289      (1.4)     38     (1.2)     1.18       (0.84-1.66)     0.33         --            --          --
   Unknown            190      (0.9)     38     (1.2)     0.78       (0.55-1.11)     0.16         --            --          --
Occupation
   Laborer           10,152   (49.5)   1,619   (50.7)    Referent                     --       Referent                     --
   Farmer            3,663    (17.9)    745    (23.3)     0.78       (0.71-0.86)    <0.001      0.93       (0.84-1.04)     0.20
   Civil servant      248      (1.2)     41     (1.3)     0.96       (0.69-1.35)     0.83       0.56       (0.38-0.80)    <0.01
   Business owner      16      (0.1)      3     (0.1)     0.85       (0.25-2.92)     0.80       0.89       (0.25-3.18)     0.85
   Merchant           617      (3.0)     91     (2.8)     1.08       (0.86-1.36)     0.50       1.07       (0.84-1.37)     0.56
   Student            575      (2.8)     74     (2.3)     1.24       (0.97-1.59)     0.09       0.98       (0.75-1.28)     0.86
   Office worker      203      (1.0)     10     (0.3)     3.24       (1.71-6.12)    <0.001      2.58       (1.33-5.01)    <0.01
   Sex worker         116      (0.6)     20     (0.6)     0.92       (0.57-1.49)     0.75       1.00       (0.60-1.66)     0.99
   Male/female bar
   worker              63     (0.3)     2      (0.1)       5.02      (1.23-20.55)    0.02       5.19       (1.25-21.53)    0.02
   Housewife         1,557    (7.6)    203     (6.4)       1.22       (1.05-1.43)    0.01       1.11        (0.94-1.32)    0.21
   Prisoner           424     (2.1)    15      (0.5)       4.51       (2.69-7.56)   <0.001      2.31        (1.35-3.95)   <0.01
   Unemployment      1,623    (7.9)    156     (4.9)       1.66       (1.40-1.97)   <0.001      1.29        (1.07-1.55)    0.01
   Other             1,243    (6.0)    214     (6.7)       0.93       (0.79-1.08)    0.33       0.87        (0.73-1.02)    0.09
Region
   Northern Region   5,157    (25.1)   1,104   (34.6)    Referent                     --       Referent                     --
   Eastern Region    1,944     (9.5)    459    (14.4)     0.91       (0.80-1.02)     0.11       1.15       (1.00-1.31)     0.04
   Northeastern
   Region            4,200    (20.5)   825     (25.8)      1.09      (0.99-1.20)     0.09       1.50       (1.35-1.68)    <0.001
   Central region    6,388    (31.2)   529     (16.6)      2.59      (2.32-2.89)    <0.001      2.44       (2.16-2.77)    <0.001
   Southern Region   2,811    (13.7)   276      (8.6)      2.18      (1.90-2.51)    <0.001      2.49       (2.14-2.90)    <0.001
Residence
   Metropolis        2,858    (14.0)    426    (13.3)    Referent                     --       Referent                     --
   Suburban          2,030     (9.9)    294     (9.2)     1.03       (0.88-1.21)     0.72       1.13       (0.95-1.34)     0.15
   Rural             12,139   (59.2)   2,158   (67.6)     0.84       (0.75-0.94)    <0.01       1.16       (1.02-1.31)     0.02
   Unknown           3,473    (16.9)    315     (9.9)     1.64       (1.41-1.92)    <0.001      1.53       (1.30-1.81)    <0.001
     *
       Patients with late diagnosis of HIV were defined as persons who had their first HIV positive test ≤ 3 months of
     diagnosis of
     AIDS; Patients with non-late diagnosis were defined as persons who had their first HIV positive test > 3 months
     of diagnosis of
     AIDS.
     †
       Confidence interval.
       The Invisible Epidemic: Factors associated with the Late Diagnosis in Thai Youth                                          63


       Table 9. Predictors of late diagnosis of HIV in young patient aged 15-24 years old, both
       unadjusted and adjusted odds ratios, Thailand, 1 January 1997- 30 June 2006
       (Changing ‘late diagnosis’ definition to 3 months, continued)
                                   Late           Non-late      Crude                                 Adjusted
                              20,483(86.5%)    3,165 (13.5%)    odds                                   odds
                                                                                     †
Characteristics              No.         (%)   No.        (%)   ratio       (95% CI )       p-value    ratio      (95% CI†)           p-value
Treatment Center
   Community hospitals§      5,835    (28.5)   1,429   (44.8)   Referent                      --      Referent                          --
   Regional/General
   hospitals§                8,776    (42.8)   1,270   (39.8)    1.69       (1.56-1.84)     <0.001      1.47      (1.35-1.61)         <0.001
   University hospitals       728      (3.5)    72      (2.3)    2.48       (1.93-3.18)     <0.001      2.56      (1.96-3.34)         <0.001
   Bangkok Metropolitan
   Administration (BMA)
   hospitals                 1,614     (7.9)     7      (0.2)    56.47     (26.82-118.90)   <0.001     58.98     (27.92-124.58)       <0.001
   Private
   hospitals/Clinics          590      (2.9)    113     (3.5)    1.28       (1.04-1.58)      0.02       0.73      (0.58-0.93)          0.01
   Health services under
   Department of Disease
   Control                   1,212     (5.9)    145     (4.5)    2.05       (1.71-2.45)     <0.001      1.49      (1.22-1.82)         <0.001
   Other¶                    1,431     (7.0)    110     (3.4)    3.19       (2.60-3.90)     <0.001      2.26      (1.80-2.85)         <0.001
   Unknown                    314      (1.5)    47      (1.5)    1.64       (1.20-2.24)     <0.01       1.17      (0.81-1.69)          0.41
Type of patient
   OPD**                     6,194    (30.2)   1,623   (50.8)   Referent                      --      Referent                          --
   IPD††                     14,286   (69.7)   1,569   (49.2)    2.39       (2.21-2.57)     <0.001      2.29      (2.11-2.49)         <0.001
   Unknown                     20      (0.1)     1      (0.0)    5.24       (0.70-39.08)     0.11       2.62      (0.34-20.34)         0.36
Sexual orientation
   Heterosexual              17,761   (86.6)   2,785   (87.2)   Referent                      --      Referent                          --
   Homosexual                 200      (1.0)    25      (0.8)    1.25       (0.83-1.90)      0.29       0.87      (0.56-1.35)          0.53
   Bisexual                    62      (0.3)     7      (0.2)    1.39       (0.64-3.04)      0.41       1.30      (0.57-2.95)          0.54
   Unknown                   2,477    (12.1)    376    (11.8)    1.03       (0.92-1.16)      0.58       0.82      (0.68-0.98)          0.03
Risk factor
   Sexual transmission       17,727   (86.5)   2,848   (89.2)   Referent                      --      Referent                          --
           §§
   IDUs                      1,231     (6.0)    122     (3.8)    1.62       (1.34-1.96)     <0.001      0.98      (0.79-1.22)          0.84
   Other                       20      (0.1)     1      (0.0)    3.21       (0.43-23.95)     0.25       3.00      (0.38-23.80)         0.30
   Unknown                   1,522     (7.4)    222     (7.0)    1.10       (0.95-1.27)      0.20       1.23      (0.99-1.53)          0.06
Numbers of AIDS-defining illnesses
   0-1                       17,597   (85.8)   3,186   (99.8)   Referent                      --      Referent                          --
   2                         2,396    (11.7)     6      (0.2)    72.30     (32.42-161.24)   <0.001     72.85     (32.63-162.64)       <0.001
   3-7                        507      (2.5)     1      (0.0)    91.79     (12.90-653.15)   <0.001     93.32     (13.09-665.33)       <0.001
Year of HIV/AIDS diagnosis
   1997-1999                 10,034   (49.0)   1,820   (57.0)   Referent                      --      Referent                          --
   2000-2002                 6,522    (31.8)   1,001   (31.3)    1.18       (1.09-1.28)     <0.001      1.22      (1.12-1.34)         <0.001
   2003-2006                 3,944    (19.2)    372    (11.7)    1.92       (1.71-2.16)     <0.001      2.44      (2.14-2.79)         <0.001
       *
         Patients with late diagnosis of HIV were defined as persons who had their first HIV positive test ≤ 3 months of
       diagnosis of AIDS; Patients with non-late diagnosis were defined as persons who had their first HIV positive
       test > 3 months of diagnosis of AIDS.
       †
          Confidence interval.
       §
          Not included hospitals in Bangkok.
       ¶
          Included hospitals under Department of correction, Department of Health, Department of Medical Services,
       Ministry of Public Health, Ministry of Defence, Ministry of Inferior and other ministries, Provincial Public
       Health Offices, Thai Red Cross, and State Enterprises.
       **
          Outpatient Department.
       ††
          Inpatient Department.
       §§
          Injecting drug users.
       Multivariate logistic models include: Gender, age group, marital status, occupation, region, residence,
       treatment center, type of patient, sexual orientation, risk factor, numbers of AIDS-defining illnesses, and year of
       HIV/AIDS diagnosis.
    64                                                                                                       C. Netima


    Table 10. Predictors of late diagnosis of HIV in young patient aged 15-24 years old, both
    unadjusted and adjusted odds ratios, Thailand, 1 January 1997- 30 June 2006
    (Changing ‘late diagnosis’ definition to 12 months)
                           Late           Non-late
                      20,564(86.8%)    3,118 (13.2%)      Crude                               Adjusted
Characteristics        No.      (%)     No.      (%)    odds ratio   (95% CI†)      p-value   odds ratio   (95% CI†)      p-value
Gender
   Male              10,085   (49.0)   1,284   (41.2)     1.37       (1.27-1.48)    <0.001     1.23        (1.12-1.36)    <0.001
   Female            10,479   (51.0)   1,834   (58.8)    Referent                             Referent
Age group
   15-16              220      (1.1)    47      (1.5)    Referent                     --      Referent                      --
   17-18              699      (3.4)    128     (4.1)     1.17       (0.81-1.68)     0.41      1.29        (0.87-1.92)     0.21
   19-20             2,335    (11.3)    448    (14.4)     1.11       (0.80-1.55)     0.52      1.19        (0.83-1.70)     0.34
   21-22             5,810    (28.3)    869    (27.9)     1.43       (1.03-1.97)     0.03      1.49        (1.05-2.12)     0.02
   23-24             11,500   (55.9)   1,626   (52.1)     1.51       (1.10-2.08)     0.01      1.58        (1.11-2.23)     0.01
Marital Status
   Married            9,078   (44.1)   1,619   (51.9)    Referent                     --      Referent                      --
   Single             9,805   (47.7)   1,202   (38.5)     1.45       (1.34-1.58)    <0.001     1.19        (1.08-1.31)    <0.001
   Separated           321     (1.6)    35      (1.1)     1.64       (1.15-2.33)     0.01      1.34        (0.92-1.95)     0.13
   Widow               747     (3.6)    145     (4.7)     0.92       (0.76-1.11)     0.37      1.09        (0.89-1.33)     0.39
   Divorce             426     (2.1)    80      (2.6)     0.95       (0.74-1.21)     0.68      1.06        (0.82-1.38)     0.66
   Unknown             187     (0.9)    37      (1.2)     0.90       (0.63-1.29)     0.57      0.80        (0.54-1.18)     0.26
Race
   Thai              20,084   (97.7)   3,044   (97.6)    Referent                    0.35         --            --          --
   Other              289      (1.4)    38      (1.2)     1.15       (0.82-1.62)     0.41         --            --          --
   Unknown            191      (0.9)    36      (1.2)     0.80       (0.56-1.15)     0.23         --            --          --
Occupation
   Laborer           10,171   (49.4)   1,594   (51.1)    Referent                     --      Referent                      --
   Farmer            3,690    (17.9)    718    (23.0)     0.81       (0.73-0.89)    <0.001     0.96        (0.86-1.07)     0.45
   Civil servant      249      (1.2)    40      (1.3)     0.98       (0.70-1.37)     0.89      0.57        (0.40-0.83)    <0.01
   Business owner      16      (0.1)     2      (0.1)     1.25       (0.29-5.46)     0.76      1.39        (0.31-6.30)     0.67
   Merchant           617      (3.0)    91      (2.9)     1.06       (0.85-1.33)     0.60      1.05        (0.82-1.33)     0.70
   Student            577      (2.8)    71      (2.3)     1.27       (0.99-1.64)     0.06      1.00        (0.76-1.31)     0.99
   Office worker      203      (1.0)    10      (0.3)     3.18       (1.68-6.02)    <0.001     2.55        (1.31-4.95)     0.01
   Sex worker         116      (0.6)    20      (0.6)     0.91       (0.56-1.47)     0.70      0.97        (0.58-1.61)     0.90
   Male/female bar
   worker               63    (0.3)     2      (0.1)       4.94      (1.21-20.19)    0.03       5.08       (1.22-21.06)    0.03
   Housewife          1,560   (7.6)    198     (6.4)       1.23       (1.06-1.44)    0.01       1.13        (0.95-1.34)    0.17
   Prisoner            425    (2.1)    14      (0.4)       4.76       (2.79-8.12)   <0.001      2.48        (1.43-4.32)   <0.01
   Unemployment       1,628   (7.9)    150     (4.8)       1.70       (1.43-2.03)   <0.001      1.33        (1.10-1.60)   <0.01
   Other              1,249   (6.1)    208     (6.7)       0.94       (0.81-1.10)    0.45       0.89        (0.75-1.05)    0.16
Region
   Northern Region    5,192   (25.2)   1,064   (34.1)    Referent                     --      Referent                      --
   Eastern Region     1,948    (9.5)    455    (14.6)     0.88       (0.78-0.99)     0.03      1.11        (0.97-1.27)     0.13
   Northeastern
   Region             4,213   (20.5)   809     (26.0)      1.07      (0.97-1.18)     0.20       1.44       (1.29-1.60)    <0.001
   Central region     6,395   (31.1)   521     (16.7)      2.52      (2.25-2.81)    <0.001      2.38       (2.10-2.70)    <0.001
   Southern Region    2,816   (13.7)   269      (8.6)      2.15      (1.86-2.47)    <0.001      2.45       (2.10-2.86)    <0.001
Residence
   Metropolis        2,864    (13.9)    419    (13.4)    Referent                     --      Referent                      --
   Suburban          2,031     (9.9)    292     (9.4)     1.02       (0.87-1.19)     0.83      1.11        (0.93-1.31)     0.25
   Rural             12,178   (59.2)   2,111   (67.7)     0.84       (0.75-0.94)    <0.01      1.15        (1.01-1.30)     0.03
   Unknown           3,491    (17.0)    296     (9.5)     1.73       (1.48-2.02)    <0.001     1.56        (1.32-1.85)    <0.001
    *
      Patients with late diagnosis of HIV were defined as persons who had their first HIV positive test ≤ 12 months
    of diagnosis of
    AIDS; Patients with non-late diagnosis were defined as persons who had their first HIV positive test > 12
    months of diagnosis of
    AIDS.
    †
      Confidence interval.
   The Invisible Epidemic: Factors associated with the Late Diagnosis in Thai Youth                                              65


   Table 10. Predictors of late diagnosis of HIV in young patient aged 15-24 years old, both
   unadjusted and adjusted odds ratios, Thailand, 1 January 1997- 30 June 2006
   (Changing ‘late diagnosis’ definition to 12 months, continued)
                              Late             Non-late
                         20,564(86.8%)      3,118 (13.2%)      Crude                                 Adjusted
Characteristics          No.        (%)     No.       (%)    odds ratio    (95% CI†)       p-value   odds ratio    (95% CI†)          p-value
Treatment Center
   Community
   hospitals§           5,864      (28.5)   1,392   (44.6)    Referent                       --      Referent                           --
   Regional/General
            §
   hospitals            8,787      (42.7)   1,257   (40.3)      1.66       (1.53-1.80)     <0.001      1.44        (1.32-1.58)        <0.001
   University hospitals 729         (3.6)   71       (2.3)      2.44       (1.90-3.13)     <0.001      2.53        (1.93-3.30)        <0.001
   Bangkok
   Metropolitan
   Administration
   (BMA) hospitals      1,614       (7.8)   7        (0.2)     54.73      (25.99-115.26)   <0.001      55.76      (26.40-117.79)      <0.001
   Private
   hospitals/Clinics    590         (2.9)   113      (3.6)      1.24       (1.01-1.53)      0.04       0.70        (0.56-0.89)        <0.01
   Health services
   under Department
   of Disease Control   1,212       (5.9)   145      (4.7)      1.98       (1.65-2.38)     <0.001      1.45        (1.18-1.77)        <0.001
   Other¶               1,432       (7.0)   109      (3.5)      3.12       (2.54-3.82)     <0.001      2.20        (1.74-2.77)        <0.001
   Unknown              336         (1.6)   24       (0.8)      3.32       (2.19-5.05)     <0.001      2.45        (1.54-3.90)        <0.001
Type of patient
   OPD**                6,226      (30.3)   1,586   (50.9)    Referent                       --      Referent                           --
   IPD††                14,318 (69.6)       1,532   (49.1)     2.38        (2.21-2.57)     <0.001     2.31         (2.13-2.51)        <0.001
   Unknown              20          (0.1)   0        (0.0)
Sexual orientation
   Heterosexual         17,799 (86.5)       2,737   (87.8)    Referent                       --      Referent                           --
   Homosexual           201         (1.0)   24       (0.8)     1.29        (0.84-1.97)      0.24      0.89         (0.57-1.40)         0.61
   Bisexual             62          (0.3)   7        (0.2)     1.36        (0.62-2.98)      0.44      1.28         (0.56-2.91)         0.56
   Unknown              2,502      (12.2)   350     (11.2)     1.10        (0.98-1.24)      0.12      0.80         (0.66-0.96)         0.02
Risk factor
   Sexual transmission  17,785 (86.5)       2,779   (89.1)    Referent                       --      Referent                           --
   IDUs§§               1,232       (6.0)   121      (3.9)     1.59         (1.31-1.93)    <0.001     0.97          (0.78-1.20)        0.75
   Other                20          (0.1)   1        (0.0)     3.13        (0.42-23.29)     0.27      2.81         (0.35-22.46)        0.33
   Unknown              1,527       (7.4)   217      (7.0)     1.10         (0.95-1.27)     0.21      1.25          (1.01-1.56)        0.04
Numbers of AIDS-defining illnesses
   0-1                  17,660 (85.9)       3,112   (99.8)    Referent                       --      Referent                           --
   2                    2,397      (11.7)   5        (0.2)     84.48      (35.10-203.32)   <0.001     84.83       (35.21-204.37)      <0.001
   3-7                  507         (2.4)   1        (0.0)     89.34      (12.56-635.71)   <0.001     90.46       (12.69-644.88)      <0.001
Year of HIV/AIDS diagnosis
   1997-1999            10,054 (48.9)       1,799   (57.7)    Referent                       --      Referent                           --
   2000-2002            6,540      (31.8)   983     (31.5)     1.19        (1.09-1.29)     <0.001     1.23         (1.12-1.34)        <0.001
   2003-2006            3,970      (19.3)   336     (10.8)     2.11        (1.87-2.39)     <0.001     2.56         (2.24-2.93)        <0.001
   *
     Patients with late diagnosis of HIV were defined as persons who had their first HIV positive test ≤ 12 months
   of diagnosis of AIDS; Patients with non-late diagnosis were defined as persons who had their first HIV positive
   test > 12 months of diagnosis of AIDS.
   †
      Confidence interval.
   §
      Not included hospitals in Bangkok.
   ¶
      Included hospitals under Department of correction, Department of Health, Department of Medical Services,
   Ministry of Public Health, Ministry of Defence, Ministry of Inferior and other ministries, Provincial Public
   Health Offices, Thai Red Cross, and State Enterprises.
   **
      Outpatient Department.
   ††
      Inpatient Department.
   §§
      Injecting drug users.
   Multivariate logistic models include : Gender, age group, marital status, occupation, region, residence,
   treatment center, type of patient, sexual orientation, risk factor, numbers of AIDS-defining illnesses, and year of
   HIV/AIDS diagnosis.
66                                                                                                       C. Netima


Figure 1. Proportion of 'late' and 'non-late' diagnosis of HIV by year (Thailand,

January 1997- June 2006). This shows a significant increasing trend in the proportion of

patients with late diagnosis of HIV infection from 1997 to 2006 (χ2 test for trend = 135.5,

p< 0.001)


                                     100



                                     95
            Percentage of patients




                                     90



                                     85


                                     80



                                  75
                               Year: 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006
                             Non-late 16.6 14.6 14.3 12.9 12.7 14.2 11.7 6.4 5.0   1.7
                             Late          83.4   85.4 85.7   87.1 87.3   85.8 88.3   93.6 95.0   98.3
     Patients/year:                        4,330 4,021 3,503 2,888 2,476 2,159 1,902 1,459 896    59
The Invisible Epidemic: Factors associated with the Late Diagnosis in Thai Youth   67


Figure 2. Map of HIV prevalence in young Thai patients aged 15-24 years old, Thailand,

January 1997– June 2006.
68                                                                         C. Netima


Figure 3. Map A. and B. show the prevalence of HIV in non-late diagnosis and late

diagnosis. Map C. shows the proportion of HIV prevalence in late diagnosis compare to

non-late diagnosis in young patients aged 15 – 24 years old, Thailand, January 1997–

June 2006.
The Invisible Epidemic: Factors associated with the Late Diagnosis in Thai Youth                                  69


Figure 4.                      Percentage of patients according to sexual orientation and transmission

category, Thailand, January 1997 – June 2006.


                               100%
                                90%
                                80%
   Percentage of patients by
    transmission category




                                70%
                                60%
                                50%
                                40%
                                30%
                                20%
                                10%
                                 0%
                                      Heterosexual       Homosexual         Bisexual        Don'know Sexual behavior
                                                                                               t

                                          IDUs       Sexaual transmission   Others     Unknown risk
70                                                                                                                                                                                                                                           C. Netima


Figure 5. Percentage of patients with late diagnosis of HIV by occupation, Thailand,

January 1997 – June 2006.


                                              100.0
                                                                                                                                                             96.9                                   96.6
 Percentage of patients with late diagnosis




                                                                                                                               95.3
                                               95.0
                                                                                                                                                                                                                91.4

                                               90.0                                                                  88.9                                                              88.5
                                                                                                          87.1
                                                      86.3               86.2
                                                                                                                                               85.3                                                                             85.5
                                                                                         84.2
                                               85.0             83.3


                                               80.0



                                               75.0


                                                                                                                                                                                        Housewife
                                                                                         Business owner




                                                                                                                                                Sex worker

                                                                                                                                                              Male/female bar worker
                                                                                                                                                                                                                                          Occupation
                                                                                                                     Student
                                                      Laborer




                                                                                                                               Office worker
                                                                Farmer




                                                                                                                                                                                                                                 Others
                                                                         Civil servant




                                                                                                          Merchant




                                                                                                                                                                                                                 Unemployment
                                                                                                                                                                                                     Prisoner
The Invisible Epidemic: Factors associated with the Late Diagnosis in Thai Youth                  71


Figure 6. Prevalence of AID-defining illnesses in late presenters, Thailand, January

1997 – June 2006.


         26%                                  23%
                                                                 Mycobacterium tuberculosis
                                                                 Pneumocystis carinii pneumonia
                                                                 Wasting syndrome
                                                                 Cryptococcocis
    4%                                                           Esophageal candidiasis
                                                    18%          Others
         12%
                             17%
72                                                                                 C. Netima


Appendix A. 2004 revised classification system for the AIDS surveillance

case definition for adults and adolescents used in Thailand



          This classification system replaces the system published by Bureau of Epidemiology,

Department of Disease Control (CDC), Ministry of Public Health in 1993 and is primarily

intended for use in public health practice. In order to diagnose patients with AIDS, a test for

HIV antibody must give a positive result. AIDS patients will be classified in to three

categories as follows:

1) All HIV infected persons who have sign/symptom of at least one disease out of the twenty-

eight diseases as described in AIDS indicative diseases.

2) All HIV infected persons who have less than 200 CD4+ T-lymphocytes/µL, or a CD4+ T-

lymphocyte percentage of total lymphocytes of less than 15, at least two times in different

testing time.

3) Patients who were infected via vertical transmission (Pediatric AIDS).

This expansion includes the addition of three clinical conditions to the twenty-five AIDS

indicative diseases

     1.   Nocardiosis

     2.   Rhodococcosis

     3.   Serious bacterial infection, recurrent or multiple

and retains the 25 clinical conditions in the AIDS surveillance case definition published in

1993.

          For AIDS category 2, the AIDS surveillance case definition was adapted to included

all HIV infected persons who have less than 200 CD4+ T-lymphocytes/µL, or a CD4+ T-
The Invisible Epidemic: Factors associated with the Late Diagnosis in Thai Youth           73


lymphocyte percentage of total lymphocytes of less than 15, at least two times in different

testing time.

These are to be used by all provinces for AIDS case reporting effective January 1, 2004.




                           Category 1. AIDS or Severe HIV disease

All HIV infected persons who have sign/symptom of at least one disease out of the twenty-

eight diseases as described in AIDS indicative diseases.

Conditions included in the 2004 AIDS surveillance case definition:

   1.   Candidiasis of esophageal, bronchi, trachea, or lungs

   Diagnostic methods:

   a) Gross inspection by endoscopy or bronchoscopy or

   b) Autopsy or by microscopy (histology or cytology) on a specimen obtained directly

        from the tissues affected (including scrapings from the mucosal surface), not from a

        culture or

   c) Candidiasis of esophagus. If not be able to perform a or b, suggested guidelines for

        presumptive diagnosis of diseases indicative of AIDS included:

        C.1 Recent onset of retrosternal pain on swallowing; AND

        C.2 Oral candidiasis diagnosed by the gross appearance of white patches or plaques

        on an erythematous base or by the microscopic appearance of fungal mycelial

        filaments from a noncultured specimen scraped from the oral mucosa.



   2.   Invasive cervical cancer

   Diagnostic methods: histology or cytology



   3.   Coccidioidomycosis, disseminated or extrapulmonary
74                                                                                     C. Netima


     Diagnostic methods:

     a) Microscopy (histology or cytology) or

     b) culture or

     c) detection of antigen in a specimen obtained directly from the tissues affected or a

          fluid from those tissues



     4.   Cryptococcosis, extrapulmonary

     Diagnostic methods:

     a) Microscopy (histology or cytology) or

     b) culture or

     c) detection of antigen in a specimen obtained directly from the tissues affected or a

          fluid from those tissues



     5.   Cryptosporidiosis, chronic intestinal (greater than 1 month's duration)

     Diagnostic methods: Microscopy (histology or cytology)



     6.   Cytomegalovirus disease (other than liver, spleen, or nodes)

     Diagnostic methods:

     a) Microscopy

     Histology or cytology



     7.   Cytomegalovirus retinitis

     Diagnostic    methods:    A     characteristic   appearance   on   serial   ophthalmo-scopic

     examinations (e.g., discrete patches of retinal whitening with distinct borders, spreading

     in a centrifugal manner along the paths of blood vessels, progressing over several months,
The Invisible Epidemic: Factors associated with the Late Diagnosis in Thai Youth             75


   and frequently associated with retinal vasculitis, hemorrhage, and necrosis). Resolution of

   active disease leaves retinal scarring and atrophy with retinal pigment epithelial mottling.



   8.   Encephalopathy, HIV-related (HIV dementia, AIDS dementia or subacute HIV

        encephalitis)

   Diagnostic methods:

   a) In adult: Clinical findings of disabling cognitive or motor dysfunction interfering with

        occupation or activities of daily living, progressing over weeks to months, in the

        absence of a concurrent illness or condition other than HIV infection that could

        explain the findings.

   b) In children: Significant abnormality of growth and development at different ages.

   -    Methods to rule out such concurrent illness and conditions must include cerebrospinal

        fluid examination and either brain imaging (computed tomography or magnetic

        resonance) or autopsy.



   9.   Herpes simplex: chronic or severe ulcer(s) in patients age greater than 1 month.

   Diagnostic methods:

   a) Chronic ulcer(s) greater than 1 month’s duration or

   b) Skin disseminated or

   c) Herpes in internal organs

   Or Specific diagnostic methods:

   a) Microscopy (histology or cytology),

   b) Culture
76                                                                                C. Netima


     10. Histoplasmosis, disseminated or extrapulmonary

     Diagnostic methods:

     a) Microscopy (histology or cytology) or

     b) culture or

     c) detection of antigen in a specimen obtained directly from the tissues affected or a

        fluid from those tissues



     11. Isosporiasis, chronic intestinal (greater than 1 month's duration)

     Diagnostic methods: Microscopy



     12. Kaposi's sarcoma

     Diagnostic methods:

     a) Microscopy or

     b) A characteristic gross appearance of an erythematous or violaceous plaque-like lesion

                                                                          s
        on skin or mucous membrane. (Note: Presumptive diagnosis of Kaposi' sarcoma

        should not be made by clinicians who have seen few cases of it.)



     13. Lymphoma, Burkitt's (or equivalent term)

     Diagnostic methods: Histology or cytology



     14. Lymphoma, immunoblastic (or equivalent term)

     Diagnostic methods: Histology or cytology



     15. Lymphoma, primary, of brain

     Diagnostic methods: Histology or cytology
The Invisible Epidemic: Factors associated with the Late Diagnosis in Thai Youth              77


   16. Mycobacterium avium complex or M. kansasii, disseminated or extrapulmonary

   Diagnostic methods: Culture



   17. Mycobacterium,        other species or unidentified species, disseminated or

       extrapulmonary

   Diagnostic methods:

   a) Culture

   b) Microscopy of a specimen from stool or normally sterile body fluids or tissue from a

       site other than lungs, skin, or cervical or hilar lymph nodes that shows acid-fast bacilli

       of a species not identified by culture.



   18. Mycobacterium tuberculosis, any site (pulmonary or extrapulmonary)

       18.1 Pulmonary TB

   Diagnostic methods:

   a) Sputum smear or culture found acid-fast bacilli

   b) pulmonary when bacteriologic confirmation is not available,

       b1. Clinical signs/symptoms and

       b2. radiologic evidence of TB, without other causes and

       b3. Response to the treatment



       18.2 Extrapulmonary TB

   Diagnostic methods:

   a) Smear or culture from normally sterile body fluids or tissue that shows acid-fast

       bacilli or

   b) Tissue Culture specific TB lesion or
78                                                                                  C. Netima


     c) Clinical signs/symptoms and response to the treatment



     19. Pneumonia, recurrent (bacterial) Recurrent (more than one episode in a 1-year

          period)

     Diagnostic methods:

     a)   x-ray evidence and stain or culture found infection



     20. Pneumocystis carinii pneumonia

     Diagnostic methods:

     a)   Microscopy found Pneumocystis carinii from induce sputum or broncho-aveolar

          larvage or

     b)   Diagnosed by three criterions

          B1. A history of dyspnea on exertion or nonproductive cough of recent onset (within

          the past 3 months); AND

          B2. Chest x-ray evidence of diffuse bilateral interstitial infiltrates or evidence by

          gallium scan of diffuse bilateral pulmonary disease; AND

          B3. No evidence of a bacterial pneumonia and response to the treatment



     21. Penicillosis from Penicillium marneffei

     Diagnostic methods: Microscopy or culture found Penicillium marneffei



     22. Progressive multifocal leukoencephalopathy

     Diagnostic methods:

     a)   Microscopy or CT scan or brain MRI found lesion or

     b)   Spinal fluid by polymerase chain reaction found JC virus DNA.
The Invisible Epidemic: Factors associated with the Late Diagnosis in Thai Youth             79


   23. Salmonella septicemia, recurrent (more than 1 time in a year period)

   Diagnostic methods: Blood culture



   24. Toxoplasmosis of brain

   Diagnostic methods:

   a)   Microscopy

   b)   Recent onset of a focal neurologic abnormality consistent with intracranial disease or

        a reduced level of consciousness; AND found at least one of the following

        B1. Evidence by brain imaging (computed tomography or nuclear magnetic

        resonance) of a lesion having a mass effect or the radiographic appearance of which

        is enhanced by injection of contrast medium; or

        B2. Spinal fluid or serum antibody to toxoplasmosis or

        B3. successful response to therapy for toxoplasmosis.



   25. Wasting syndrome (Emaciation, Slim disease) due to HIV

   Diagnostic methods: Findings of profound involuntary weight loss of greater than 10% of

   baseline body weight plus either chronic diarrhea (at least two loose stools per day for

   greater than or equal to 30 days), or chronic weakness and documented fever (for greater

   than or equal to 30 days, intermittent or constant) in the absence of a concurrent illness or

   condition other than HIV infection that could explain the findings (e.g., cancer,

   tuberculosis, cryptosporidiosis, or other specific enteritis).
80                                                                               C. Netima


     26. Nocardiosis

     Diagnostic methods:

     a) Detection of antigen in a specimen obtained directly from the tissues affected or a

        fluid from those tissues culture or

     b) Culture



     27. Rhodococcosis

     Diagnostic methods:

     a) Detection of antigen in a specimen obtained directly from the tissues affected or a

        fluid from those tissues culture or

     b) Culture



     28. Serious bacterial infection, recurrent or multiple (at least 2 times in 2 years) in

        patients age less than 13 years old (serious bacterial infection such as septicemia,

        severe lung infection, meningitis, bone or joint infection or abscess in internal

        organ.

     Diagnostic methods: Culture



                  Category 2. AIDS diagnosed by CD4 count or CD4 percentage

HIV antibody must give a positive result and CD4 count is less than 200 /µL, or a CD4+ T-

lymphocyte percentage of total lymphocytes of less than 15 , at least two times in different

testing time in order to confirm the result.




Source: Thailand. MoPH. Thai Surveillance case definition for AIDS and HIV infection [in
Thai]. Weekly Epidemiology Surveillance Report. 2003;34(suppl):1-36.
The Invisible Epidemic: Factors associated with the Late Diagnosis in Thai Youth             81


Appendix B. 1993 revised classification system for HIV infection and

expanded surveillance case definition for AIDS among adolescents and

adults


The following CDC staff members prepared this report:

National Center for Infectious Diseases Division of HIV/AIDS Kenneth G. Castro, M.D.

John W. Ward, M.D. Laurence Slutsker, M.D., M.P.H. James W. Buehler, M.D. Harold W.

Jaffe, M.D. Ruth L. Berkelman, M.D.

Office of the Director Associate Director for HIV/AIDS James W. Curran, M.D., M.P.H.

1993 Revised Classification System for HIV Infection and Expanded Surveillance Case

Definition for AIDS Among Adolescents and Adults



Summary

CDC has revised the classification system for HIV infection to emphasize the clinical

importance of the CD4+ T-lymphocyte count in the categorization of HIV-related clinical

conditions. This classification system replaces the system published by CDC in 1986 (1) and

is primarily intended for use in public health practice. Consistent with the 1993 revised

classification system, CDC has also expanded the AIDS surveillance case definition to

include all HIV-infected persons who have less than 200 CD4+ T-lymphocytes/µL, or a

CD4+ T-lymphocyte percentage of total lymphocytes of less than 14. This expansion

includes the addition of three clinical conditions

   4.   pulmonary tuberculosis, recurrent pneumonia, and invasive cervical cancer -- and

        retains the 23 clinical conditions in the AIDS surveillance case definition published in

        1987 (2); it is to be used by all states for AIDS case reporting effective January 1,

        1993.
82                                                                                C. Netima


REVISED HIV CLASSIFICATION SYSTEM FOR ADOLESCENTS AND ADULTS

The etiologic agent of acquired immunodeficiency syndrome (AIDS) is a retrovirus

designated human immunodeficiency virus (HIV). The CD4+ T-lymphocyte is the primary

target for HIV infection because of the affinity of the virus for the CD4 surface marker (3).

The CD4+ T-lymphocyte coordinates a number of important immunologic functions, and a

loss of these functions results in progressive impairment of the immune response. Studies of

the natural history of HIV infection have documented a wide spectrum of disease

manifestations, ranging from asymptomatic infection to life-threatening conditions

characterized by severe immunodeficiency, serious opportunistic infections, and cancers (4-

13). Other studies have shown a strong association between the development of life-

threatening opportunistic illnesses and the absolute number (per microliter of blood) or

percentage of CD4+ T- lymphocytes (14-21). As the number of CD4+ T-lymphocytes

decreases, the risk and severity of opportunistic illnesses increase.

Measures of CD4+ T-lymphocytes are used to guide clinical and therapeutic management of

HIV-infected persons (22). Antimicrobial prophylaxis and antiretroviral therapies have been

shown to be most effective within certain levels of immune dysfunction (23-28). As a result,

antiretroviral therapy should be considered for all persons with CD4+ T-lymphocyte counts

of less than 500/µL, and prophylaxis against Pneumocystis carinii pneumonia (PCP), the

most common serious opportunistic infection diagnosed in men and women with AIDS, is

recommended for all persons with CD4+ T-lymphocyte counts of less than 200/µL and for

persons who have had prior episodes of PCP. Because of these recommendations, CD4+ T-

lymphocyte determinations are an integral part of medical management of HIV-infected

persons in the United States.

The classification system for HIV infection among adolescents and adults has been revised to

include the CD4+ T-lymphocyte count as a marker for HIV-related immunosuppression. This
The Invisible Epidemic: Factors associated with the Late Diagnosis in Thai Youth                 83


revision establishes mutually exclusive subgroups for which the spectrum of clinical

conditions is integrated with the CD4+ T-lymphocyte count. The objectives of these changes

are to simplify the classification of HIV infection, to reflect current standards of medical care

for HIV-infected persons, and to categorize more accurately HIV-related morbidity.

The revised CDC classification system for HIV-infected adolescents and adults * categorizes

persons on the basis of clinical conditions associated with HIV infection and CD4+ T-

lymphocyte counts. The system is based on three ranges of CD4+ T- lymphocyte counts and

three clinical categories and is represented by a matrix of nine mutually exclusive categories

(Table 1). This system replaces the classification system published in 1986, which included

only clinical disease criteria and which was developed before the widespread use of CD4+ T-

cell testing (1).

    •   Criteria for HIV infection for persons ages greater than 13 years:

    a. repeatedly reactive screening tests for HIV antibody (e.g., enzyme immunoassay)

        with specific antibody identified by the use of supplemental tests (e.g., Western blot,

        immunofluorescence assay);

    b. direct identification of virus in host tissues by virus isolation; c) HIV antigen

        detection; or d) a positive result on any other highly specific licensed test for HIV.

CD4+ T-Lymphocyte Categories

The three CD4+ T-lymphocyte categories are defined as follows:

    •   Category 1: greater than or equal to 500 cells/µ L

    •   Category 2: 200-499 cells/µL

    •   Category 3: less than 200 cells/µ L

These categories correspond to CD4+ T-lymphocyte counts per microliter of blood and guide

clinical and therapeutic actions in the management of HIV-infected adolescents and adults
84                                                                                   C. Netima


22-28). The revised HIV classification system also allows for the use of the percentage of

CD4+ T-cells (Appendix B part I).

HIV-infected persons should be classified based on existing guidelines for the medical

management of HIV-infected persons (22). Thus, the lowest accurate, but not necessarily the

most recent, CD4+ T-lymphocyte count should be used for classification purposes.

Clinical Categories

The clinical categories of HIV infection are defined as follows: Category A

Category A consists of one or more of the conditions listed below in an adolescent or adult

(greater than or equal to 13 years) with documented HIV infection. Conditions listed in

Categories B and C must not have occurred.

     •   Asymptomatic HIV infection

     •   Persistent generalized lymphadenopathy

     •   Acute (primary) HIV infection with accompanying illness or history of acute HIV

         infection (29,30) Category B

Category B consists of symptomatic conditions in an HIV-infected adolescent or adult that

are not included among conditions listed in clinical Category C and that meet at least one of

the following criteria: a) the conditions are attributed to HIV infection or are indicative of a

defect in cell-mediated immunity; or b) the conditions are considered by physicians to have a

clinical course or to require management that is complicated by HIV infection. Examples of

conditions in clinical Category B include, but are not limited to:

     •   Bacillary angiomatosis

     •   Candidiasis, oropharyngeal (thrush)

     •   Candidiasis, vulvovaginal; persistent, frequent, or poorly responsive to therapy

     •   Cervical dysplasia (moderate or severe)/cervical carcinoma in situ
The Invisible Epidemic: Factors associated with the Late Diagnosis in Thai Youth          85


   •   Constitutional symptoms, such as fever (38.5 C) or diarrhea lasting greater than 1

       month

   •   Hairy leukoplakia, oral

   •   Herpes zoster (shingles), involving at least two distinct episodes or more than one

       dermatome

   •   Idiopathic thrombocytopenic purpura

   •   Listeriosis

   •   Pelvic inflammatory disease, particularly if complicated by tubo-ovarian abscess

   •   Peripheral neuropathy

For classification purposes, Category B conditions take precedence over those in Category A.

For example, someone previously treated for oral or persistent vaginal candidiasis (and who

has not developed a Category C disease) but who is now asymptomatic should be classified

in clinical Category B.

Category C

Category C includes the clinical conditions listed in the AIDS surveillance case definition

(Appendix B part II). For classification purposes, once a Category C condition has occurred,

the person will remain in Category C.



EXPANSION OF THE CDC SURVEILLANCE CASE DEFINITION FOR AIDS

In 1991, CDC, in collaboration with the Council of State and Territorial Epidemiologists

(CSTE), proposed an expansion of the AIDS surveillance case definition. This proposal was

made available for public comment in November 1991 and was discussed at an open meeting

on September 2, 1992. Based on information presented and reviewed during the public

comment period and at the open meeting, CDC, in collaboration with CSTE, has expanded

the AIDS surveillance case definition to include all HIV-infected persons with CD4+ T-
86                                                                                   C. Netima


lymphocyte counts of less than 200 cells/µ L or a CD4+ percentage of less than 14. In

addition to retaining the 23 clinical conditions in the previous AIDS surveillance definition,

the expanded definition includes pulmonary tuberculosis (TB), recurrent pneumonia, and

invasive cervical cancer. * This expanded definition requires laboratory confirmation of HIV

infection in persons with a CD4+ T-lymphocyte count of less than 200 cells/µ L or with one

of the added clinical conditions. This expanded definition for reporting cases to CDC

becomes effective January 1, 1993.

     •   Diagnostic criteria for AIDS-defining conditions included in the expanded

         surveillance case definition are presented in Appendix B part III and Appendix B part

         IV.

In the revised HIV classification system, persons in subcategories A3, B3, and C3 meet the

immunologic criteria of the surveillance case definition, and those persons with conditions in

subcategories C1, C2, and C3 meet the clinical criteria for surveillance purposes.



COMMENTARY Revised Classification System

The revised classification system for HIV infection is based on the recommended clinical

standard of monitoring CD4+ T- lymphocyte counts, since this parameter consistently

correlates with HIV-related immune dysfunction and disease progression and provides

information needed to guide medical management of persons infected with HIV (14-18, 22-

28). The classification system also allows for use of the percentage of CD4+ T-cells instead

of absolute CD4+ T-lymphocyte counts (Appendix B part I). Other markers of immune status

-- such as serum neopterin, beta-2 microglobulin, HIV p24 antigen, soluble interleukin-2

receptors, immunoglobulin A, and delayed-type hypersensitivity (DTH) skin-test reactions --

may be useful in the evaluation of individual patients but are not as strongly predictive of

disease progression or as specific for HIV-related immunosuppression as measures of CD4+
The Invisible Epidemic: Factors associated with the Late Diagnosis in Thai Youth                87


T-lymphocytes (14-21, 31). DTH skin-test reactions are often used in conjunction with the

Mantoux tuberculin skin test to evaluate HIV-infected patients for TB infection and anergy

(31-33).

Other systems have been proposed for classification and staging of HIV infection (1, 31, 34-

39). In 1990, the World Health Organization (WHO) published an interim proposal for a

staging system for HIV infection and diseases that was based primarily on clinical criteria

and included the use of CD4+ T-lymphocyte determinations (34). The WHO system

incorporates a performance scale and total lymphocyte counts to be used in lieu of CD4+ T-

lymphocyte determinations in countries where CD4+ T-lymphocyte testing is not available.

The accuracy of CD4+ T-lymphocyte counts is important for medical care of individual

patients. To assure reliability, laboratories conducting CD4+ T-lymphocyte measurements

should be experienced with test procedures, have established quality assurance methods, and

participate in proficiency testing programs conducted by CDC or other organizations (22, 40).

CDC has published guidelines for the performance of CD4+ T-cell determinations for HIV-

                                                                              s
infected persons (41). To assure that test results are indicative of a patient' medical condition,

the health-care provider should evaluate the results with those of earlier tests and with the

       s
patient' clinical condition. In clinical practice, repeat CD4+ testing may be judged necessary

in guiding therapeutic decisions for individual patients. For surveillance purposes, however, a

requirement for repeat CD4+ determinations is impractical for population-based monitoring.

The revised classification system of the clinical and immunologic manifestations of HIV

infection   provides    a    framework      for   categorizing    HIV-related      morbidity   and

immunosuppression and will assist efforts to evaluate the overall impact of the HIV epidemic.

Knowledge of the spectrum of clinical conditions and the extent of immunosuppression that

may occur during the course of HIV infection is important for prompt evaluation and for
88                                                                                  C. Netima


provision of appropriate health services. Clinicians should be aware of the clinical conditions

suggestive of HIV infection and the need for prophylactic and therapeutic interventions.

This revised HIV classification system should be used by state and territorial health

departments that conduct HIV infection surveillance. Because AIDS surveillance data will

continue to represent only a portion of the total morbidity caused by HIV, surveillance for

HIV infection may be particularly useful in depicting the total impact of HIV on health-care

and social services (42). More accurate reporting and analysis of CD4+ T-lymphocyte counts,

together with HIV-related clinical conditions, should facilitate efforts to evaluate health-care

and referral needs for persons with HIV infection and to project future needs for these

services.



Expanded AIDS Surveillance Case Definition

The population of HIV-infected persons with CD4+ T-lymphocyte counts of less than 200/µL

is substantially larger than the population of persons with AIDS-defining clinical conditions

(43). The inclusion in the AIDS surveillance definition of persons with a CD4+ T-

lymphocyte count of less than 200 cells/µL or a CD4+ percentage less than 14 will enable

AIDS surveillance to reflect more accurately the number of persons with severe HIV-related

immunosuppression and those at highest risk for severe HIV-related morbidity. Since the

AIDS surveillance case definition was last revised in 1987, the increasing use of prophylaxis

against PCP and antiretroviral therapy for persons infected with HIV has slowed the rate at

which HIV-infected persons develop AIDS-defining clinical conditions (2,22-25). For

example, among homosexual/bisexual men with AIDS reported to CDC, the proportion with

PCP decreased from 62% in 1988 to 46% in 1990 (44). This trend is expected to continue.

The ability of clinicians to report HIV-infected persons on the basis of CD4+ T-lymphocyte

counts may also simplify the case-reporting process. A simplified AIDS surveillance case
The Invisible Epidemic: Factors associated with the Late Diagnosis in Thai Youth                89


definition will be particularly important for outpatient clinics in which the availability of staff

to conduct surveillance is limited and from which an increasing proportion of AIDS cases are

being reported. For example, from pre-1985 to 1988, the proportion of AIDS cases reported

from outpatient sites in the state of Washington increased from 6% (9/155) to 25% (55/219)

(45). A similar increase occurred in Oregon (25% {44/171} before 1987 to 38% {40/105} in

the first half of 1989) (46).



Pulmonary Tuberculosis

Throughout the world, pulmonary TB is the most common type of TB in persons with HIV

infection (47). The addition of pulmonary TB to the list of AIDS-indicator diseases is based

on the strong epidemiologic link between HIV infection and the development of TB (48-50).

Persons co-infected with HIV and TB have a substantially increased risk of developing active

TB compared with persons without HIV infection (48, 49). In a prospective evaluation of

injecting-drug users (IDUs) with positive tuberculin skin tests, the estimated annual incidence

of active TB among 49 HIV-infected IDUs was 7.9 cases/100 person-years; however, no

cases of active TB occurred among 62 tuberculin-positive but HIV-seronegative IDUs

followed for as long as 30 months (48).

There is also a substantial immunologic association between HIV-infected persons and

pulmonary TB when compared with HIV-infected persons with extrapulmonary TB (a

condition included in the 1987 surveillance definition). In a recent review, median CD4+ T-

lymphocyte counts in HIV-infected patients with pulmonary TB ranged from 250 to 500

cells/µL (51). In comparison, the median CD4+ lymphocyte count was 242 cells/µL in one

study of persons with localized extrapulmonary TB and ranged from 70 to 79 cells/µL in two

                                                                   s
studies of patients with disseminated or miliary TB (51-53). In CDC' Adult and Adolescent

Spectrum of HIV Disease (ASD) Project, 69% of HIV-infected persons with pulmonary TB
90                                                                                 C. Netima


had CD4+ T-lymphocyte counts of less than 200/µL, compared with 77% of persons with

extrapulmonary TB (CDC, unpublished observations).

The addition of pulmonary TB to AIDS surveillance criteria will require continued

                                                                                      s
collaboration between state and local TB and HIV/AIDS programs. Knowledge of a patient'

HIV status is important for the proper medical management of TB because longer courses of

therapy and prophylaxis are recommended for HIV-infected patients with TB (54).

Furthermore, HIV-infected TB patients should be a priority for epidemiologic investigation

because these persons are more likely to have HIV-infected contacts than are seronegative

TB patients. TB contact follow-up among HIV-infected persons will help to ensure delivery

of a full course of preventive therapy to these contacts, who are at greatly increased risk of

developing active TB themselves.



Recurrent Pneumonia

With the exception of conditions included in the 1987 AIDS surveillance case definition,

pneumonia, with or without a bacteriologic diagnosis, is the leading cause of HIV-related

morbidity and death (55, 56). In addition, several studies have shown that persons with HIV-

related immunosuppression are at an increased risk of bacterial pneumonia (57-59). For

example, one study found that the yearly incidence rate of bacterial pneumonia among HIV-

infected IDUs without AIDS was five times that found in non-HIV-infected IDUs (58).

Recurrent episodes of pneumonia (two or more episodes within a 1-year period) are required

for AIDS case reporting because pneumonia is a relatively common diagnosis and multiple

episodes of pneumonia are more strongly associated with immunosuppression than are single

episodes. For example, data from the ASD Project indicate that the risk of an HIV-infected

person having had one episode of pneumonia in a 12-month period is approximately five

times higher among infected persons with CD4+ T-lymphocyte counts of less than 200/µL
The Invisible Epidemic: Factors associated with the Late Diagnosis in Thai Youth           91


(320/2,411) than among those with higher CD4+ T-lymphocyte counts (90/2,792). In contrast,

data from the same study indicate that the risk for multiple episodes of pneumonia in a 12-

month period is approximately 20 times higher among HIV-infected persons with CD4+ T-

lymphocyte counts of less than 200/µL (67/2,411) than among those with higher CD4+ T-cell

counts (4/2,792) (CDC, unpublished observations).



Invasive Cervical Cancer

Several studies have found an increased prevalence of cervical dysplasia, a precursor lesion

for cervical cancer, among HIV-infected women (60, 61). In a study of 310 HIV-infected

women attending methadone maintenance and sexually transmitted disease clinics in New

York City and Newark, New Jersey, cervical dysplasia was confirmed by biopsy and/or

colposcopy in approximately 22%, a prevalence rate 10 times greater than that found among

women attending family planning clinics in the United States (Wright TC, personal

communication; 62). Several studies have documented that a higher prevalence of cervical

dysplasia among HIV-infected women is associated with greater immunosuppression (Wright

TC, personal communication; 61,63). In addition, HIV infection may adversely affect the

clinical course and treatment of cervical dysplasia and cancer (64-69).

Invasive cervical cancer is a more appropriate AIDS-indicator disease than is either cervical

dysplasia or carcinoma in situ because these latter cervical lesions are common and

frequently do not progress to invasive disease (70). Also, cervical dysplasia or carcinoma in

situ among women with severe cervicovaginal infections, which are common in HIV-infected

women, can be difficult to diagnose. In contrast, the diagnosis of invasive cervical cancer is

generally unequivocal.

Invasive cervical cancer is preventable by the proper recognition and treatment of cervical

dysplasia. Thus, the occurrence of invasive cervical cancer among all women -- including
92                                                                                 C. Netima


those who are HIV-infected -- represents missed opportunities for disease prevention. The

addition of invasive cervical cancer to the list of AIDS-indicator diseases emphasizes the

importance of integrating gynecologic care into medical services for HIV-infected women.



Impact on AIDS Case Reporting

The expanded AIDS surveillance case definition is expected to have a substantial impact on

the number of reported cases. The immediate increase in case reporting will be largely

attributable to the addition of severe immunosuppression to the definition; a smaller impact is

expected from the addition of pulmonary TB, recurrent pneumonia, and invasive cervical

cancer, since many persons with these diseases will also have CD4+ T-lymphocyte counts of

less than 200 cells/µL. If all of the approximately 1,000,000 persons in the United States with

HIV infection were diagnosed and their immune status were known, it is estimated that

120,000- 190,000 persons who do not have AIDS-indicator diseases would be found to have

CD4+ T-lymphocyte counts of less than 200 cells/µL (71). However, not all of these persons

are aware of their HIV infection and of those who know their HIV infection status, not all

have had an immunologic evaluation; thus, the immediate impact on the number of AIDS

cases will be considerably less than 120,000- 190,000. If AIDS surveillance criteria were

unchanged, approximately 50,000-60,000 reported AIDS cases would be expected in 1993.

Based on current levels of HIV and CD4+ testing, CDC estimates that the expanded

definition could increase cases reported in 1993 by approximately 75%. Early effects of

expanded surveillance will be greater than long-term effects because prevalent as well as

incident cases of immunosuppression will be reported following implementation of the

expanded surveillance case definition. In subsequent years, the effect on the number of

reported cases is expected to be much smaller.
The Invisible Epidemic: Factors associated with the Late Diagnosis in Thai Youth            93


Uses of the HIV Classification System or AIDS Surveillance Case Definition

The revised HIV classification system and the AIDS surveillance case definition are intended

                                                         s
for use in conducting public health surveillance. The CDC' AIDS surveillance case

definition was not developed to determine whether statutory or other legal requirements for

entitlement to Federal disability or other benefits are met. Consequently, this revised

surveillance case definition does not alter the criteria used by the Social Security

Administration in evaluating claims based on HIV infection under the Social Security

disability insurance and Supplemental Security Income programs. Other organizations and

agencies providing medical and social services should develop eligibility criteria appropriate

to the services provided and local needs.



Confidentiality

The confidentiality of AIDS case reports -- including laboratory reports of HIV test results,

CD4+ T-lymphocyte test results, and medical records under review by health department

staff -- is of critical importance to maintaining effective HIV/AIDS surveillance. CDC and

state health departments have implemented procedures and policies to maintain

                                                                    s
confidentiality and security of HIV/AIDS surveillance data (72). CDC' efforts include a

federal assurance of confidentiality, the removal of names before encrypted records are

transmitted to CDC, strict guidelines for the release of aggregate data, and the inclusion of

confidentiality and security safeguards as evaluation criteria for federal funding of state

HIV/AIDS surveillance activities (73). These strict criteria will continue to apply to cases

reported under the expanded definition. CDC funding of surveillance cooperative agreements

                             s
is dependent on the recipient' ability to ensure the physical security of case reports and on

state policies or laws to protect the confidentiality of persons reported with AIDS. Failure to
94                                                                                  C. Netima


ensure the security and confidentiality of personal identifying information collected as part of

AIDS or HIV surveillance activities will jeopardize federal surveillance funding.

CD4+ T-lymphocyte test results reported by laboratories will be an important adjunct to

medical record review and provider-initiated reporting in order to increase completeness,

timeliness, and efficiency of AIDS surveillance. Information from a laboratory-initiated

report of a CD4+ T-lymphocyte count is insufficient for reporting a case of AIDS.

Confirmation of HIV infection status and receipt of other surveillance information from the

health-care provider or from medical or public health records will remain necessary.

Every effort should be made by health-care providers, laboratories, and public health

agencies to protect the confidentiality of CD4+ T-lymphocyte test results, including the

review of record-keeping practices in laboratories and health-care settings. Some states have

considered additional means to assure the confidentiality of CD4+ T-lymphocyte test results.

For example, a proposal in Oregon would allow health-care providers to send specimens to

laboratories for CD4+ T-lymphocyte testing with a unique code for each person being tested.

If the test result indicates a CD4+ T-lymphocyte count of less than 200 cells/µL, the health

department would notify the health-care provider that an AIDS case report is required if the

person is HIV infected, the CD4+ T-lymphocyte count is valid, and the case has not been

previously reported. Informed consent for CD4+ T-lymphocyte testing should be obtained in

accordance with local laws or regulations. CD4+ T-lymphocyte test results alone should not

be used as a surrogate marker for HIV or AIDS. A low CD4+ T-lymphocyte count without a

positive HIV test result will not be reportable since other conditions may result in a low

CD4+ T-lymphocyte count. Health-care providers must ensure that persons who have a

CD4+ T-lymphocyte count of less than 200/µL are HIV infected before initiating treatment

for HIV disease or reporting those persons as cases of AIDS.
The Invisible Epidemic: Factors associated with the Late Diagnosis in Thai Youth            95


CONCLUSION

The revised HIV classification system provides uniform and simple criteria for categorizing

conditions among adolescents and adults with HIV infection and should facilitate efforts to

evaluate current and future health-care and referral needs for persons with HIV infection. The

addition of a measure of severe immunosuppression, as defined by a CD4+ T-lymphocyte

count of less than 200 cells/µL or a CD4+ percentage of less than 14, reflects the standard of

immunologic monitoring for HIV-infected persons and will enable AIDS surveillance data to

more accurately represent those who are recognized as being immunosuppressed, who are in

greatest need of close medical follow-up, and who are at greatest risk for the full spectrum of

severe HIV-related morbidity. The addition of three clinical conditions -- pulmonary TB,

recurrent pneumonia, and invasive cervical cancer -- to AIDS surveillance criteria reflects the

documented or potential importance of these diseases in the HIV epidemic. Two of these

conditions (pulmonary TB and cervical cancer) are preventable if appropriate screening tests

are linked with proper follow-up. The third, recurrent pneumonia, reflects the importance of

pulmonary infections not included in the 1987 definition as leading causes of HIV-related

morbidity and mortality. Successful implementation of expanded surveillance criteria will

require the extension of existing safeguards to protect the security and confidentiality of

AIDS surveillance information.




Appendix B part I. Equivalences for CD4+ T-lymphocyte count and percentage of total

lymphocytes
96                                                                                C. Netima


Compared with the absolute CD4+ T-lymphocyte count, the percentage of CD4+ T-cells of

total lymphocytes (or CD4+ percentage) is less subject to variation on repeated measurements

(18,74). However, data correlating natural history of HIV infection with the CD4+ percentage

have not been as consistently available as data on absolute CD4+ T-lymphocyte counts (14-

16,18,19,21,31). Therefore, the revised classification system emphasizes the use of CD4+ T-

lymphocyte counts but allows for the use of CD4+ percentages.

Equivalences (Table A1) were derived from analyses of more than 15,500 lymphocyte subset

determinations from seven different sources: one multistate study of diseases in HIV-infected

adolescents and adults (59) and six laboratories (two commercial, one research, and three

university-based). The six laboratories are involved in proficiency testing programs for

lymphocyte subset determinations. In the analyses, concordance was defined as the

proportion of patients classified as having CD4+ T-lymphocyte counts in a particular range

among patients with a given CD4+ percentage. A threshold value of the CD4+ percentage

was calculated to obtain optimal concordance with each stratifying value of the CD4+ T-

lymphocyte counts (i.e., less than 200/µL and greater than or equal to 500/µL). The

thresholds for the CD4+ percentages that best correlated with a CD4+ T-lymphocyte count of

less than 200/µL varied minimally among the seven data sources (range, 13%-14%; median,

13%; mean, 13.4%). The average concordance for a CD4+ percentage of less than 14 and a

CD4+ T-lymphocyte count of less than 200/µL was 90.2%. The threshold for the CD4+

percentages most concordant with CD4+ T-lymphocyte counts of greater than or equal to

500/µL varied more widely among the seven data sources (range, 22.5%-35%; median, 29%;

mean, 29.1%). This wide range of percentages optimally concordant with greater than or

equal to 500/µL CD4+ T-lymphocytes makes the concordance at this stratifying value less

certain. The average concordance for a CD4+ percentage of greater than or equal to 29 and a

CD4+ T-lymphocyte count of greater than or equal to 500/µL was 85% (CDC, unpublished
The Invisible Epidemic: Factors associated with the Late Diagnosis in Thai Youth        97


data). Clinicians and other practitioners must recognize that these suggested equivalences

may not always correspond with values observed in individual patients.




Appendix B part II. Conditions included in the 1993 AIDS surveillance case definition

   29. Candidiasis of bronchi, trachea, or lungs
98                                                                                    C. Netima


     30. Candidiasis, esophageal

     31. Cervical cancer, invasive *

     32. Coccidioidomycosis, disseminated or extrapulmonary

     33. Cryptococcosis, extrapulmonary

                                                                    s
     34. Cryptosporidiosis, chronic intestinal (greater than 1 month' duration)

     35. Cytomegalovirus disease (other than liver, spleen, or nodes)

     36. Cytomegalovirus retinitis (with loss of vision)

     37. Encephalopathy, HIV-related

                                                               s
     38. Herpes simplex: chronic ulcer(s) (greater than 1 month' duration); or bronchitis,

        pneumonitis, or esophagitis

     39. Histoplasmosis, disseminated or extrapulmonary

                                                               s
     40. Isosporiasis, chronic intestinal (greater than 1 month' duration)

               s
     41. Kaposi' sarcoma

                          s
     42. Lymphoma, Burkitt' (or equivalent term)

     43. Lymphoma, immunoblastic (or equivalent term)

     44. Lymphoma, primary, of brain

     45. Mycobacterium avium complex or M. kansasii, disseminated or extrapulmonary

     46. Mycobacterium tuberculosis, any site (pulmonary * or extrapulmonary)

     47. Mycobacterium,     other      species   or   unidentified   species,   disseminated   or

        extrapulmonary

     48. Pneumocystis carinii pneumonia

     49. Pneumonia, recurrent *

     50. Progressive multifocal leukoencephalopathy

     51. Salmonella septicemia, recurrent

     52. Toxoplasmosis of brain
The Invisible Epidemic: Factors associated with the Late Diagnosis in Thai Youth     99


   53. Wasting syndrome due to HIV

   •   Added in the 1993 expansion of the AIDS surveillance case definition.




Appendix B part III. Definitive diagnostic methods for diseases indicative of AIDS
100                                                                                   C. Netima


                                       s
Cryptosporidiosis, Isosporiasis, Kaposi' sarcoma, Lymphoma, Pneumocystis carinii

pneumonia, Progressive multifocal leukoencephalopathy, Toxoplasmosis, Cervical cancer

Microscopy (histology or cytology)

Candidiasis Gross inspection by endoscopy or autopsy or by microscopy (histology or

cytology) on a specimen obtained directly from the tissues affected (including scrapings from

the mucosal surface), not from a culture

Coccidioidomycosis,       Cryptococcosis,      Cytomegalovirus,    Herpes     simplex     virus,

Histoplasmosis Microscopy (histology or cytology), culture, or detection of antigen in a

specimen obtained directly from the tissues affected or a fluid from those tissues

Tuberculosis, Other mycobacteriosis, Salmonellosis Culture

HIV encephalopathy (dementia) Clinical findings of disabling cognitive or motor dysfunction

interfering with occupation or activities of daily living, progressing over weeks to months, in

the absence of a concurrent illness or condition other than HIV infection that could explain

the findings. Methods to rule out such concurrent illness and conditions must include

cerebrospinal fluid examination and either brain imaging (computed tomography or magnetic

resonance) or autopsy.

HIV wasting syndrome Findings of profound involuntary weight loss of greater than 10% of

baseline body weight plus either chronic diarrhea (at least two loose stools per day for greater

than or equal to 30 days), or chronic weakness and documented fever (for greater than or

equal to 30 days, intermittent or constant) in the absence of a concurrent illness or condition

other than HIV infection that could explain the findings (e.g., cancer, tuberculosis,

cryptosporidiosis, or other specific enteritis).

Pneumonia, recurrent Recurrent (more than one episode in a 1-year period), acute (new x-ray

evidence not present earlier) pneumonia diagnosed by both: a) culture (or other organism-

specific diagnostic method) obtained from a clinically reliable specimen of a pathogen that
The Invisible Epidemic: Factors associated with the Late Diagnosis in Thai Youth
101


typically causes pneumonia (other than Pneumocystis carinii or Mycobacterium tuberculosis),

and b) radiologic evidence of pneumonia; cases that do not have laboratory confirmation of a

causative organism for one of the episodes of pneumonia will be considered to be

presumptively diagnosed.
102                                                                                     C. Netima


Appendix B part IV. Suggested guidelines for presumptive diagnosis of diseases indicative

of AIDS

Candidiasis of esophagus

      a. Recent onset of retrosternal pain on swallowing; AND

      b. Oral candidiasis diagnosed by the gross appearance of white patches or plaques on an

         erythematous base or by the microscopic appearance of fungal mycelial filaments

         from a noncultured specimen scraped from the oral mucosa.

Cytomegalovirus retinitis A characteristic appearance on serial ophthalmo-scopic

examinations (e.g., discrete patches of retinal whitening with distinct borders, spreading in a

centrifugal manner along the paths of blood vessels, progressing over several months, and

frequently associated with retinal vasculitis, hemorrhage, and necrosis). Resolution of active

disease leaves retinal scarring and atrophy with retinal pigment epithelial mottling.

Mycobacteriosis Microscopy of a specimen from stool or normally sterile body fluids or

tissue from a site other than lungs, skin, or cervical or hilar lymph nodes that shows acid-fast

bacilli of a species not identified by culture.

      s
Kaposi' sarcoma A characteristic gross appearance of an erythematous or violaceous plaque-

                                                                              s
like lesion on skin or mucous membrane. (Note: Presumptive diagnosis of Kaposi' sarcoma

should not be made by clinicians who have seen few cases of it.)

Pneumocystis carinii pneumonia

    a. A history of dyspnea on exertion or nonproductive cough of recent onset (within the

         past 3 months); AND

    b. Chest x-ray evidence of diffuse bilateral interstitial infiltrates or evidence by gallium

         scan of diffuse bilateral pulmonary disease; AND
The Invisible Epidemic: Factors associated with the Late Diagnosis in Thai Youth
103


      c. Arterial blood gas analysis showing an arterial pO((2)) of less than 70 mm Hg or a

         low respiratory diffusing capacity (less than 80% of predicted values) or an increase

         in the alveolar-arterial oxygen tension gradient; AND

      d. No evidence of a bacterial pneumonia.

Pneumonia, recurrent Recurrent (more than one episode in a 1-year period), acute (new

symptoms, signs, or x-ray evidence not present earlier) pneumonia diagnosed on clinical or

                                 s
radiologic grounds by the patient' physician.

Toxoplasmosis of brain

      a. Recent onset of a focal neurologic abnormality consistent with intracranial disease or

         a reduced level of consciousness; AND

      b. Evidence by brain imaging (computed tomography or nuclear magnetic resonance) of

         a lesion having a mass effect or the radiographic appearance of which is enhanced by

         injection of contrast medium; AND

      c. Serum antibody to toxoplasmosis or successful response to therapy for toxoplasmosis.

Tuberculosis, pulmonary when bacteriologic confirmation is not available, other reports may

be considered to be verified cases of pulmonary        y tuberculosis if the criteria of the

Division of Tuberculosis Elimination, National Center for Prevention Services, CDC, are

used. The criteria in use as of January 1, 1993, are available in MMWR 1990;39 (No. RR-

13):39- 40.




Source: Centers for Disease Control and Prevention. 1993 revised classification system for
HIV infection and expanded surveillance definition for AIDS among adolescents and adults.
MMWR. 1992; 41(RR-17):1-19. Available at
http://www.cdc.gov/MMWR/preview/mmwrhtml/00018871.htm . Accessed January, 2006.

				
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