Combination HIV prevention among MSM in South Africa: results from agent-based modeling

• Published in: PloS one Vol. 9; no. 11; p. e112668
• Main Authors: Brookmeyer, Ron, Boren, David, Baral, Stefan D, Bekker, Linda-Gail, Phaswana-Mafuya, Nancy, Beyrer, Chris, Sullivan, Patrick S
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science 14.11.2014; Public Library of Science (PLoS)
• Subjects: Acquired immune deficiency syndrome; Agent-based models; AIDS; Analysis; Anti-HIV Agents - therapeutic use; Antiretroviral agents; Antiretroviral drugs; Antiretroviral therapy; CD4 antigen; Combined Modality Therapy - methods; Computer simulation; Confidence intervals; Disease prevention; Disease transmission; Drug therapy; Epidemics; Epidemiology; Generalized linear models; Genetic Testing - methods; HIV; HIV Infections - prevention & control; HIV tests; Homosexuality, Male; Human immunodeficiency virus; Human rights; Humans; Infections; Intervention; Male; Medicine and Health Sciences; Mens health; Models, Biological; Packages; Pre-Exposure Prophylaxis - methods; Prevention; Public health; Reduction; Research and Analysis Methods; Risk taking; Safe Sex - psychology; Sexually transmitted disease prevention; Sexually transmitted diseases; Social sciences; South Africa; STD; Systematic review; Variables; South Africa; Los Angeles California; United States > US; California; Peru; Maryland; Baltimore Maryland
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0112668

HIV prevention trials have demonstrated the effectiveness of a number of behavioral and biomedical interventions. HIV prevention packages are combinations of interventions and offer potential to significantly increase the effectiveness of any single intervention. Estimates of the effectiveness of prevention packages are important for guiding the development of prevention strategies and for characterizing effect sizes before embarking on large scale trials. Unfortunately, most research to date has focused on testing single interventions rather than HIV prevention packages. Here we report the results from agent-based modeling of the effectiveness of HIV prevention packages for men who have sex with men (MSM) in South Africa. We consider packages consisting of four components: antiretroviral therapy for HIV infected persons with CD4 count <350; PrEP for high risk uninfected persons; behavioral interventions to reduce rates of unprotected anal intercourse (UAI); and campaigns to increase HIV testing. We considered 163 HIV prevention packages corresponding to different intensity levels of the four components. We performed 2252 simulation runs of our agent-based model to evaluate those packages. We found that a four component package consisting of a 15% reduction in the rate of UAI, 50% PrEP coverage of high risk uninfected persons, 50% reduction in persons who never test for HIV, and 50% ART coverage over and above persons already receiving ART at baseline, could prevent 33.9% of infections over 5 years (95% confidence interval, 31.5, 36.3). The package components with the largest incremental prevention effects were UAI reduction and PrEP coverage. The impact of increased HIV testing was magnified in the presence of PrEP. We find that HIV prevention packages that include both behavioral and biomedical components can in combination prevent significant numbers of infections with levels of coverage, acceptance and adherence that are potentially achievable among MSM in South Africa.