Purpose: � With more than 400,000 annual new HIV infections in South Africa, scaling up prevention is an urgent priority.� Many experts believe a portfolio of interventions is the best strategy for controlling the epidemic.� We aimed to evaluate the cost-effectiveness of HIV intervention portfolios in South Africa, to maximize health benefits given limited resources. ��
Methods: � We developed a dynamic HIV transmission model to evaluate combinations of HIV screening, antiretroviral therapy (2010 guidelines), male circumcision, vaccination, and vaginal microbicide use. �The model includes disease transmission, progression, morbidity, and mortality among adults aged 15-49 in South Africa.� Initial conditions were based on demographic, epidemiologic, and behavioral data, and parameters were adjusted using trial data on intervention efficacy.� Three trials in sub-Saharan Africa indicated that male circumcision reduced transmission in heterosexual men by 48-60%; a 2009 Thailand trial found a vaccine regimen conferring 31% protection; a 2010 South Africa vaginal tenofovir microbicide trial indicated a 39% transmission reduction in women. Calculated outcomes include incidence, prevalence, quality-adjusted life years (QALYs), and cost-effectiveness.� We extended our deterministic results to include a Monte Carlo simulation and probabilistic cost-effectiveness analysis to account for uncertainty in each intervention's efficacy.
Results: � Under the status quo, 1.43 million (men) and 1.64 million (women) new infections occur over 10 years.� Increased male circumcision is cost-saving, reducing infections by 19% (men) and 7% (women).� Broad use of a vaginal microbicide reduces incidence by 30% (women) and 11% (men) due to reduced secondary transmission, for $750/QALY assuming an annual microbicide cost of $100.� Extensive vaccination reduces cases by 26%, for $880/QALY assuming $500 per vaccination series.� A program offering circumcision, microbicides, and vaccination has diminishing returns, preventing 43% of cases.� Alternatively, increased screening and antiretroviral therapy reduces incidence by 45%, for $800/QALY.� A portfolio with all five interventions averts 69% of infections, and is cost-effective at $1,860/QALY.� Monte Carlo simulation results suggest that such a strategy costs <$5,000/QALY in 87% of trials, and <$10,000/QALY in 94% of trials.
Conclusions: � A comprehensive portfolio of expanded HIV screening, antiretroviral therapy, male circumcision, vaccination, and microbicide use prevents the greatest number of infections and is cost-effective.� Male circumcision is cost-saving, but differentially benefits men.� Given resource constraints, the model can help identify the optimal portfolio of interventions.�