3 Community mobilisation, Thailand’s 100% Condom Program Pilot in Ratchaburi provinceImplementation on a national scaleStructural approaches that have sought to reduce the HIV vulnerability of sex workers have ranged from policies to enforce condom use to programmes that sought to build solidarity among and empower sex workers. Assessment of the 100% condom use policy in Thailand revealed that condom use climbed to over 90% (figure 3).40 Similar outcomes were reported from a more recent study of the effect of a 100% condom use policy combined with efforts to build community solidarity among sex workers in Puerto Plata in the Dominican Republic (panel 4).41Figure 3 Full-size image (42K)Increase in condom use reported by sex workers in sentinel serosurveillanceReproduced with permission form UNAIDS.40Proportion of condom use with Reported STD nationallyrecent clientsSource: UNAIDS Case Study: Evaluation of the 100% Condom Programme in Thailand, 2000.
4 HIV Prevalence Declines in Pregnant Women As this slide shows, there have also been declines in HIV prevalence in pregnant women in recent years. There are a number of effective HIV prevention methods available today, including safer sex, safer injection practices, condom use, and male circumcision. There are, however, also social obstacles attached to each of these. And we have seen that, even when these interventions are fully funded and supported by states and social institutions, they have only been able to drive HIV infection rates down to a certain level. In order to further reduce HIV incidence we need new biomedical tools -- the most important of these will be an effective HIV vaccine.Source: National surveillance reports and UNAIDS/WHO/UNICEF, Epidemiological Fact Sheets on HIV and AIDS. July 2008.
5 Behavioural change, impact in urban and semi-urban Zimbabwe M1: assuming behavioural change, better fit to surveillance dataNatural decline in incidence ~1990Accelerated decline in incidence, due to behaviour change ~2000M0: without behavioural changeFitted models for Zimbabwe data in urban and semi-urban areas.The posterior modal simulation is plotted for model M0 (without behaviour change: dashed blue line); and for model M1 (with behaviour change: solid black line). The prevalence data are also shown as grey crosses and lines.HIV incidence (per 100 person years at risk) for the entire posterior sample of simulations is plotted. Each thin grey line is one simulation, the thick red line is the mode, and the dashed black lines show the 2.5th and 97.5th percentiles of the distribution of prevalence.Source: Hallett TB, et al. Epidemics 2009;1(2):
6 R0 = β c D Basic reproductive rate Transmission probability Mean duration of infectionCondom useARTMicrobicidesPrEPPMTCTCircumcisionClean needlesVCTARTMean number of contactsVCTBehavioural changeSubstitution therapy
7 Effectiveness of condoms in preventing STIs including HIV This review of prospective studies published identified evidence that consistent condom use is associated with reduced transmission in HIVSource: Holmes KK, et al. Bull World Health Organ. 2004;82(6):
8 Source: UNAIDS, UNICEF & WHO, 2008; data provided by countries. Number and percentage of HIV-positive pregnant women receiving antiretroviral prophylaxis200420062005Number of HIV-positive pregnant women receiving anti-retroviralsYear% of HIV-positive pregnant womenreceiving anti-retrovirals5303515202540102007Only 35% of HIV positive pregnant women receiving ARTSource: UNAIDS, UNICEF & WHO, 2008; data provided by countries.
9 Reduction of acquisition risk after male circumcision (A) South Africa(B) Kenya(C) Uganda>50% reduction in risk of acquisition for menInfection-Free ProbabilityCumulative sero-incidenceCumulative probabilities of HIV detectionSource: (A) Auvert B, et al. PLoS Med 2005;2(11): e298, (B) Bailey RC, et al. Lancet 2007; 369:643–656 and (C)Gray RH, et al. Lancet 2007; 369:657–666.
10 RCT: Treatment of STIsSource: Ronald Gray, Plenary lecture - Biomedical HIV Prevention Trials (A Sisyphean Task). Cape Town, IAS conference July 2009.
13 ConcurrencyStrong case in modelling for concurrency as a determinant of HIV in southern AfricaBUTEmpirical evidence is lackingPolygyny protectiveMore research needed on sexual networksStandard definitions needed for concurrencyWhat is the intervention?
14 Population impact of treatment as prevention Time trends resulting from application of universal voluntary HIV testing and immediate ART strategy for people who test HIV positive, in combination with other adult prevention interventions that reduce incidence by 40%Source: Granich RM, et al. Lancet 2009; 373: 48–57.
17 Source: Hallett TB, et al. PLoS ONE 2008;3(5): e2212 Interaction of circumcision interventions with existing behaviour change programmesFour epidemic projections show: (i) no interventions, (ii) circumcision intervention with 90% coverage, (iii) a behaviour change intervention that leads to an average 30% reduction in partner change rate and 30% increase in condom use with casual partners, (iv) both the circumcision intervention and the behaviour change intervention. The output is HIV incidence per 100 person-years at risk (pyar). The time-scale relates to years since the circumcision intervention starts. (Note: Unlike in other simulations, here no compensation is made for the potential effects of AIDS mortality modifying the risk distribution in the populationProjected effect of different prevention interventions on HIV incidenceSource: Hallett TB, et al. PLoS ONE 2008;3(5): e2212
18 Effectiveness /efficacy and controversies Rates of HIV infection during typical and perfect useSource: Cates W. Technical advances in HIV prevention, in HIV/AIDS Annual Update In: Phair JP, ed. Clinical Care Options, 2006.
19 Know your epidemic Cambodia, 1988-2004 5000100001500020000250003000035000400004500019881989199019911992199319941995199619971998199920002001200220032004Male clientsSex workersWife from husbandHusband from wifeMother to childNumber of new HIV infections by route of transmissionSource: Peerapatanapokin and Brown, using Asia Epidemic Model
20 Know your epidemic Lithuania 20042008Proportion of HIV diagnosed cases by transmission categorySource: Strujeva O , et al. Poster CDC079 – HIV infection trends in Lithuania in 2004 – Cape Town, IAS conference July 2009.
21 Source: www.avac.org/timeline-website/ HIV Prevention Research Time-line of Expected Efficacy Trial Results (AVAC)200720082009201020112012+STEP (HVTN 502/ Merck 023)HSV-2 SUPPRESSION (HPTN 039)HPTN 035CDC 4323iPrExCDC 4940PHAMBILIMale Circumcision in HIV+ MenPARTNERS IN PREVENTIONCDC 4370PARTNERS PrEPMIRACARRAGUARDALVAC-AIDSVAXCAPRISA 004FEM-PrEPMDP 301HVTN 505VOICE (MTN-003)HPTN 052Source:
23 The prevention gapTo have an impact with already efficient prevention methods, we need more coveragePercentage of population groups most at risk with access to prevention services, 2008Source: WHO/UNICEF/UNAIDS. Towards Universal Access. Scaling up priority HIV/AIDS interventions in the health sector. Progress report 2009.
28 The long term viewStop generic response to heterogeneous problemStart structural interventions NOWInvest in professionals and institutionsDonor indicators and incentives focus on long term impactMaximise programme efficiencyR&D