PubMed | University of Winnipeg, London School of Hygiene and Tropical Medicine and Medical Research Council Unit on AIDS Uganda Virus Research Institute
Type: Journal Article | Journal: Sexually transmitted infections | Year: 2014
Antiretroviral therapy (ART) availability in a population may influence risky sexual behaviour. We examine the potential impact of ART on the HIV epidemic, incorporating evidence for the impact that ART may have on risky sexual behaviour.A mathematical model, parameterised using site-specific data from Uganda and worldwide literature review, was used to examine the likely impact of ART on HIV epidemiologic trends. We varied assumptions about rates of initiating ART, and changes in sexual partner turnover rates.Modelling suggests that ART will reduce HIV incidence over 20 years, and increase prevalence. Even in the optimistic scenario of ART enrollment beginning after just five months of infection (in HIV stage 2), prevalence is estimated to rise from a baseline of 10.5% and 8.3% among women and men, respectively, to at least 12.1% and 10.2%, respectively. It will rise further if sexual disinhibition occurs or infectiousness while on ART is slightly higher (2% female to male, rather than 0.5%). The conditions required for ART to reduce prevalence over this period are likely too extreme to be achievable. For example, if ART enrolment begins in HIV stage 1 (within the first 5 months of infection), and if risky sexual behaviour does not increase, then 3 of our 11 top fitting results estimate a potential drop in HIV prevalence by 2025. If sexual risk taking rises, it will have a large additional impact on expected HIV prevalence. Prevalence will rise despite incidence falling, because ART extends life expectancy.HIV prevalence will rise. Even small increases in partner turnover rates will lead to an additional substantial increase in HIV prevalence. Policy makers are urged to continue HIV prevention activities, including promoting sex education, and to be prepared for a higher than previously suggested number of HIV infected people in need of treatment.
PubMed | Medical Research Council Unit on AIDS Uganda Virus Research Institute
Type: Journal Article | Journal: AIDS (London, England) | Year: 2011
To assess evidence for sexual behavior change in response to antiretroviral therapy (ART) among members of a Ugandan clinical cohort. Secondarily, to examine factors associated with both sexual behavior and ART independently, that may help to assess the impact that ART is likely to have on the HIV epidemic.Retrospective analysis of data from an open cohort.ART roll-out began in the cohort in 2004. Using 3-monthly data from 2002 to 2009, we conducted regression and descriptive analyses to examine associations between timing of ART initiation and sexual behavior among HIV-infected, and timing of ART availability and sexual behavior among HIV-uninfected. We also examined partner turnover rates, and the proportion of HIV-infected on ART - two important factors for modeling the potential impact of ART on the HIV epidemic.Risky sexual behavior among HIV-infected people rose on several indicators after ART initiation, but not to levels higher than two or more years before initiation. Some evidence suggests that the availability of ART may impact risky behavior among HIV-uninfected people, although this was inconsistent across different reported behavior variables.The HIV-uninfected is larger than the HIV-infected population. If risky behavior among this population increases due to the feeling of safety that ART provides, this will affect the impact of ART on the HIV epidemic. Policy makers are urged to intensify messages associating sexual behavior and HIV and to target both HIV-infected and uninfected people.