Vol. 58 / No. 21 MMWR 589
References immunodeficiency syndrome [AIDS] diagnosis) was based on
1. CDC. Update: swine influenza A (H1N1) infections—California and the 1,021 diagnoses in 2006 among persons aged >13 years
Texas, April 2009. MMWR 2009;58:435–7.
2. CDC. Outbreak of swine-origin influenza A (H1N1) virus infection— reported to CDC by the Puerto Rico Department of Health
Mexico, March–April 2009. MMWR 200958:467–70. through June 2007. Data were categorized by sex, age group,
3. Dirección General Adjunta de Epidemiología. Brote de influenza A and mode of HIV transmission. The following hierarchy was
H1N1 México. Boletín Diario 22 (May 18, 2009).
4. Viboud C, Alonso WJ, Simonsen L. Influenza in tropical regions. PLoS used for HIV transmission categories: 1) male-to-male sexual
Med 2006;3:e89. contact, 2) injection-drug use, 3) male-to-male sexual contact
5. World Health Organization. Human infection with new influenza A and injection-drug use, and 4) high-risk heterosexual contact
(H1N1) virus: clinical observations from Mexico and other affected
countries, May 2009. Wkly Epidemiol Rec 2009;84:185–9.
(i.e., with a sex partner known to have or to be at high risk
6. CDC. Hospitalized patients with novel influenza A (H1N1) virus for HIV infection). The number of reported diagnoses was
infection—California, April–May, 2009. MMWR 2009;58:536–41. adjusted for reporting delay using a previously reported proce-
7. CDC. Serum cross-reactive antibody response to a novel influenza A dure (3). In addition, for diagnosed cases missing transmission
(H1N1) virus after vaccination with seasonal influenza vaccine. MMWR
2009;58:521–4. category (32%), a multiple imputation procedure was used (4).
8. CDC. Swine-origin influenza A (H1N1) virus infections in a school— Percentages were calculated for sex, age group, and transmission
New York City, April 2009. MMWR 2009;58:470–2. categories. HIV diagnosis rates per 100,000 population were
9. Kohn MA, Farley TA, Sundin D, Tapia R, McFarland LM, Arden
NH. Three summertime outbreaks of influenza type A. J Infect Dis calculated for sex and age group using postcensus estimates
1995;172:246–9. for 2006 (5).
10. Taubenberger JK, Morens DM. 1918 influenza: the mother of all pan- HIV incidence for Puerto Rico was calculated using the
demics. Emerg Infect Dis 2006;12:15–22.
stratified extrapolation approach (2,6). Remnant diagnostic
serum specimens from persons aged >13 years and diagnosed
with HIV infection in 2006 in Puerto Rico were tested with the
BED HIV-1 capture enzyme immunoassay (BED) to classify
Incidence and Diagnoses of HIV infections as recent or long-standing. In addition to the BED
Infection — Puerto Rico, 2006 result, the estimation method requires HIV testing history,
demographic data, and behavioral information for persons
In 2006, 33 U.S. states and five territories had confidential,
with HIV infection diagnosed in 2006. HIV incidence was
name-based, human immunodeficiency virus (HIV) infection
calculated from cases based on the 1,021 diagnoses of HIV
reporting; among territories, Puerto Rico had the second high-
infection, adjusted to 1,460 for reporting delays in 2006.
est rate of HIV infection (1). To characterize the HIV epidemic
Percentages were calculated for sex, age group, and transmis-
in Puerto Rico in 2006 (the year with the most recent available
sion categories. HIV incidence rates per 100,000 population
data), the Puerto Rico Department of Health and CDC ana-
were calculated for sex and age group using official postcensus
lyzed data on diagnoses of HIV infection (including infections
estimates for 2006 (5).
that occurred in 2006 and in previous years) and used a strati-
In 2006, after adjustment for reporting delays, 1,460 per-
fied extrapolation approach developed by CDC (2) to generate
sons aged >13 years were diagnosed with HIV infection in
HIV incidence estimates (the number of persons newly infected
Puerto Rico (Table 1). Of these, 1,036 (71%) were males and
with HIV in 2006). The results indicated that, in 2006, an
424 (29%) were females. By age group, the greatest number
estimated 1,440 persons aged >13 years wer