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AIDS Prevention in Generalized Epidemics

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					AIDS Prevention in Africa’s
  Generalized Epidemics
      What should we be doing?
        What are we doing?

A Review of HIV/AIDS Prevention in the
  National Strategic Planning Process
        In sub-Saharan Africa

            July 24, 2012
 Sponsored by World Bank /
   UNAIDS (ESA) / UNFPA

 Norman Hearst, Allison Herling Ruark
         and Nicole Fraser

         conceptual guidance
  Marelize Gorgens and Helen Jackson
           peer review input
Clemens Benedict, Helen Epstein, Daniel
      Halperin and James Shelton
What should we be doing?
Review of scientific literature

What are we doing?
Desk review of documents related to the
national strategic planning process from 12
sub-Saharan African countries

Practical policy implications
    Presentations at this Session
• I will present:
  Methods for the first two parts of this review
  Results of scientific literature review
• Subsequent speakers will present:
  Results of the NSP process review - Benedikt
  A practical experience (Kenya) - Ombam
  Policy recommendations - Gorgens
• Panel discussion / questions
           NSP Process Review

Included countries in eastern and southern Africa
  with generalized HIV epidemics:

  Botswana                   South Africa
  Kenya                      Swaziland
  Lesotho                    Tanzania
  Malawi                     Uganda
  Mozambique                 Zambia
  Namibia                    Zimbabwe
         Sources of Information
• National Strategic Plans and Frameworks (NSP/NSF)
• Know Your Epidemic/Know Your Response (KYE/KYR)
  and Modes of Transmission (MoT) analyses
• National AIDS Spending Assessments (NASA)
• United Nations General Assembly Special Session
  (UNGASS) Reports
• Midterm reviews by UN Country Coordinators
• Other associated documents
• Key informants
      Methods (country review)
• Collect and review documents
• Complete data abstraction form (guided by
  literature review)
• Search elsewhere for missing items
• Record observations and comments
• “Results” are tabulations, case examples, and
  general process and outcome observations
• Looked for common trends
• Policy implications
       Limitations of this Analysis
• Documents often vague; specific information not
  always available
• Documents sometimes give conflicting data
• No country-by-country validation
• Budgetary data often retrospective and several years
  old
• NSPs on different 5-year cycles that don’t coincide
• Plans are only plans and may not reflect reality
• Many NSPs promise quick ramp-up, so situation may
  have improved recently (but previous NSPs also
  promised quick ramp-up)
• Errors and judgment calls by reviewers
     Scientific Literature Review
        (What should we be doing?)
• Computerized literature search
• Additional references from citations in initial
  publications
• “Missing” key citations filled in by colleagues
  through vetting and peer review
• DHS data analysis conducted by 2 of the
  authors; separate from this review
• Not covered: blood safety and preventing
  nosocomial infection
         Types of HIV epidemics
• Concentrated (none of these 12 countries)
Transmission in specific high risk settings or subgroups
  (e.g., MSM, IDU, commercial sex) drives epidemic;
  overall population prevalence usually low
• Generalized
Transmission in general population drives epidemic; can
  produce very high rates; mainly in Africa;
  “hyperepidemic” when pop. prevalence > 15%
• Mixed
Transmission self-sustaining both in high risk subgroups
  AND in general population.
  HIV Transmission in Advanced Generalized HIV Epidemics in Africa
                                    (need to consider country-level differences)

                                                                                                                      ῀20 % among
               ῀80 % of new infections among adults 15+3                                                                children3

? IDU,                                                                                      Blood/                   ? Abuse
0-4%2          MSM    (1-8%2)                                                               injections


                                                                                                                          Vertical
               Heterosexual transmission (81%-99% of adult                                 infections2)
                                                                                                                       transmission



      Co-facilitated by low levels of male circumcision (& other biological factors)

     Sex work
     + clients +
                     Multiple including concurrent partnerships,                   Transmission within
      partners       casual sex (and partner change due to separation, widowhood      stable couples
     (3 -16 %2)                                 etc.)                              (10-38% of adult infections3)




 Sources:
 1) UNAIDS:
 Global Report
 2010                   Dynamic effects
 2) MOT analyses,
 5 countries
 3) Laith et al.                  Socio-economic, socio-cultural factors,                                          Overstretched
 (2012, in review)
                                             gender, stigma                                                        health systems
  Levels of evidence for strategies to
reduce population-wide HIV incidence
   in Africa’s generalized epidemics
Categories:
• Proven interventions
• Not fully proven interventions
• Interventions with Emerging Evidence
• Interventions with Lack of Evidence
• Disproven Interventions
         Proven interventions
• Proven to reduce HIV incidence at the
  individual level in ideal conditions (efficacy)
  [Usually from participants in research studies]
                        AND
• Evidence of population-level impact in real-
  world conditions (effectiveness)
  [Usually from population-based data]
Only BIOLOGICAL outcomes (usually HIV rates)
   Not fully proven interventions
• Promising interventions for which either
  1) evidence of population-level effectiveness in
    reducing HIV incidence exists, but evidence for
    efficacy of specific interventions is lacking or
    ambiguous, or
  2) evidence of individual-level efficacy in reducing
    HIV incidence exists, but evidence of effectiveness
    in reducing HIV incidence at a population level in
    real world settings is lacking
Interventions with Emerging Evidence
 More recent; just a few studies


Interventions with Lack of Evidence
 Not new, but lacking good evidence


Disproven Interventions
 Demonstrated not to work for HIV prevention
Proven Interventions
  Male Circumcision
  Prevention of Mother to Child Transmission (PMTCT)
  Interventions for Identifiable Sex Worker Populations
Not Fully Proven Interventions
  Sexual behavior change (MCP)
  Condom Promotion
  Anti-Retroviral Treatment as Prevention
Interventions with Emerging Evidence
  Economic Empowerment for Women
Interventions with Lack of Evidence
  HIV Testing and Counseling (HTC)
  Interventions for Men Who Have Sex with Men
  Harm Reduction Interventions for Injecting Drug Users
Disproven Interventions
  Treatment of Sexually Transmitted Infections (STIs)
           Male Circumcision
• Evidence from 3 RCTs shows lower HIV
  incidence among circumcised men
• Strong association in generalized epidemics
  between level of male circumcision and
  population-level HIV prevalence in both men
  and women
• Programatic experience shows reasonable
  uptake in many populations
   Prevention of mother to child
      transmission (PMTCT)
• Evidence from 9 RCTs shows reduced HIV
  incidence among neonates through use of anti
  -retrovirals in perinatal period
• PMTCT services have clearly reduced HIV
  infection among newborns in many countries
• BUT little impact on wider epidemics (at least,
  until children would reach sexual maturity)
 Interventions for Identifiable Sex
       Worker Populations
• Trials early in the epidemic established
  efficacy of condom promotion and STI
  treatment in Nairobi, Kinshasa, etc with
  reduced HIV incidence in sex workers.
• Public health effectiveness suggested by
  modeling
• BUT most sex work in Africa is not in brothels
  or other concentrated/identifiable sites
• Formal sex work is not the major driver of
  generalized African epidemics.
        Disproven interventions
                    STI treatment

• First trial appeared to show efficacy
• But 8 subsequent trials of syndromic and mass STI
  treatment have found no impact on HIV incidence
• Important in its own right and has synergies with HIV
  prevention, but proven not to be effective (on the
  population level) for preventing HIV infection
Interventions with Lack of Evidence
         (in generalized epidemics)
• Interventions for Men Who Have Sex with
  Men
• Harm Reduction Interventions for Injecting
  Drug Users
No studies with biological outcomes from
  generalized or mixed epidemics in Africa
Individual impact may be similar to that in
  concentrated epidemics, but population
  impact likely to be much smaller
Interventions with Lack of Evidence
                 HIV counseling and testing
•   Meta-analysis: those who test positive generally
    increase condom use; those who test negative do
    not (Weinhardt et al. 1999)
•   Three RCTs show no difference in HIV incidence in
    those tested (Corbett et al. 2007; Sherr et al. 2007;
    VCT Study Group 2000)
•   Testing may increase condom use among sero-
    discordant couples, and those who use condoms
    consistently have lower incidence, but “intention to
    treat” efficacy is not clear.
•   No evidence for population-level effectiveness
      DHS analysis of HIV Testing
   (Hearst, Ruark, Green et al; not part of WB/UNAIDS/UNFPA project)

• N = 48,298 in Côte d’Ivoire, Swaziland,
  Tanzania, and Zambia
• Examined association between knowing HIV
  status and condom use
• Knowing status only made a consistent
  difference for people in a stable couple who
  were HIV+.
• BUT consistent condom use remained low,
  even for these people (10% to 40%).
     Bottom Line on HIV Testing
• An important TOOL, but NOT prevention by
  itself
• Essential for treatment and some prevention
  strategies (PMTCT, ARVs for prevention)
• Does not automatically or even usually result
  in positive behavior change
• Best evidence for effectiveness is identifying
  discordant couples for intensive intervention
  and follow-up; even then, most discordant
  couples continue to have unprotected sex
Interventions with Emerging Evidence
          Economic empowerment of women

• Different strategies have been tried, and more
  evidence is needed to establish efficacy
• A community RCT which provided microfinance to
  poor women in South Africa found no impact on HIV
  incidence (Pronyk et al. 2006)
• A cluster RCT in Malawi found that a conditional cash
  transfer to girls and young women decreased sexual
  activity and reduced HIV incidence by 60% (Baird et al.
  2006)
   Not Fully Proven Interventions
     Sexual behavior change (reducing MCP)
• Having multiple partners is clearly an individual risk factor.
• In “natural experiments,” such as in Uganda, Zimbabwe, and
  other African countries, significant national-level decline in
  HIV infections has followed changes in sexual behavior,
  particularly reduction in number of sexual partners among
  adults
• Little evidence regarding the programatic impact of
  interventions intended to produce such behavior change
• RCTs of behavioral interventions for youth have failed to
  show impact on HIV incidence (Cowan et al. 2010; Jewkes et al.
  2008; Ross et al. 2007), though some show changes in self-
  reported behavior or pregnancy
   Not Fully Proven Interventions
                   Condom promotion
• Male and female condoms have high efficacy, with male
  condoms reducing HIV transmission by 80-90% at the
  individual level
• However the population-level effectiveness of condom
  promotion seems to be much less, due to low uptake and lack
  of correct and consistent condom use among users, risk
  compensation
• No study has clearly shown a population-wide decrease in HIV
  incidence in a generalized epidemic in response to condom
  promotion
• Some mathematical models suggest population-wide impact
  on HIV-incidence from condom use; others do not
    Model Favoring Public Health
       Impact of Condoms
• Modeling of epidemic in South Africa 2000-2008
  (Johnson et. al. 2012)
• HIV incidence in adults fell 27-31% over this period.
• 23-37% of that decline may have been due to
  increased condom use.
• Weaknesses: Results depend on model assumptions
• Similar models in past projected large numbers of
  infections averted, even as epidemic was growing
  exponentially
• Models are not evidence; they simply show what
  scenarios are plausible
 DHS Data Suggest Limited Impact
      of Condoms in Africa
   (Hearst, Ruark, Green et al; not part of WB/UNAIDS/UNFPA project)


• N = 48,298 in Côte d’Ivoire, Swaziland, Tanzania, and
  Zambia
• Among people who don’t know their HIV status, is
  condom use protective? (People who know their
  status excluded from analysis in case this might
  cause condom use.)
• Both unadjusted and adjusted analysis (age, income,
  urban/rural, 2+ partners in past year)
   Not Fully Proven Interventions
               Biomedical Interventions (1)
• Clinical trials suggest efficacy, but more evidence is
  needed to establish effectiveness in real-world
  settings
• HIV vaccine: After several failed trials, an RCT of an
  HIV vaccine has shown a 31% reduction in HIV
  incidence
• Vaginal microbicide: After a number of failed trials,
  the CAPRISA trial showed 39% reduction in HIV
  incidence and 54% among high adherers
        Biomedical Interventions (2)
                Treatment as Prevention

• Pre-exposure prophylaxis (PrEP): After several failed
  trials, 3 RCTs announced successful results in 2010 and
  2011
   – 44-73% reduction in HIV incidence treated individuals
• Early ART for known discordant couples: Treatment of
  infected partner at CD4 350-550 reduced HIV
  transmission by 96% vs. treatment at CD4 < 250 (Cohen
  et al. 2011)
• “Community viral load”: High levels of viral suppression
  may reduce population-wide incidence
 Treatment as Prevention (cont’d)
BUT
• You need very high levels of treatment coverage
  (80+% ?), high adherence, consistent viral load
  suppression, excellent long term follow-up,
  access to second and third-line drugs
• Most African countries do not have enough
  treatment slots to treat even people with
  advanced immunosuppression
• Behavioral disinhibition
• No evidence yet for community effectiveness in
  generalized epidemics
         Bottom line on TasP
Likely an important addition to the prevention
armamentarium, but unlikely to be the “magic
bullet”

Even if treatment turns out to be good prevention,
prevention will always be the best treatment.

We will need treatment along with all the other
modes of prevention for the foreseeable future. The
challenge will be to make them work synergistically.
Proven Interventions
  Male Circumcision
  Prevention of Mother to Child Transmission (PMTCT)
  Interventions for Identifiable Sex Worker Populations
Not Fully Proven Interventions
  Sexual behavior change (MCP)
  Condom Promotion
  Anti-Retroviral Treatment as Prevention
Interventions with Emerging Evidence
  Economic Empowerment for Women
Interventions with Lack of Evidence
  HIV Testing and Counseling (HTC)
  Interventions for Men Who Have Sex with Men
  Harm Reduction Interventions for Injecting Drug Users
Disproven Interventions
  Treatment of Sexually Transmitted Infections (STIs)

				
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