title: Epidemiological impact of tenofovir gel on the HIV epidemic in South Africa.
abstract: BACKGROUND
  Tenofovir gel, an antiretroviral-based vaginal microbicide, reduced HIV acquisition by 39% in women in a recent randomized controlled clinical trial in South Africa.
  
  
  METHODS
  To inform policy, we used a dynamical model of HIV transmission, calibrated to the epidemic in South Africa, to determine the population-level impact of this microbicide on HIV incidence, prevalence, and deaths and to evaluate its cost-effectiveness.
  
  
  RESULTS
  If women use tenofovir gel in 80% or more of sexual encounters (high coverage), it could avert 2.33 (0.12 to 4.63) million new infections and save 1.30 (0.07 to 2.42) million lives and if used in 25% of sexual encounters (low coverage), it could avert 0.50 (0.04 to 0.77) million new infections and save 0.29 (0.02 to 0.44) million deaths, over the next 20 years. At US $0.50 per application, the cost per infection averted at low coverage is US $2392 (US $562 to US $4222) and the cost per disability-adjusted life year saved is US $104 (US $27 to US $181); at high coverage the costs are about 30% less.
  
  
  CONCLUSIONS
  Over 20 years, the use of tenofovir gel in South Africa could avert up to 2 million new infections and 1 million AIDS deaths. Even with low rates of gel use, it is highly cost-effective and compares favorably with other control methods. This female-controlled prevention method could have a significant impact on the epidemic of HIV in South Africa. Programs should aim to achieve gel use in more than 25% of sexual encounters to significantly alter the course of the epidemic.
authors.affiliation: South African Centre for Epidemiological Modelling and Analysis (SACEMA), Stellenbosch, South Africa. briangerardwilliams@gmail.com
authors.forename: Brian G
authors.initials: BG
authors.lastname: Williams
authors.forename: Salim S
authors.initials: SS
authors.lastname: Abdool Karim
authors.forename: Quarraisha Abdool
authors.initials: QA
authors.lastname: Karim
authors.forename: Eleanor
authors.initials: E
authors.lastname: Gouws
mesh_terms: D000225:Adenine / Q000008:administration & dosage / Q000031:analogs & derivatives* / Q000627:therapeutic use; D019380:Anti-HIV Agents / Q000008:administration & dosage* / Q000627:therapeutic use; D003362:Cost-Benefit Analysis; D005260:Female; D015658:HIV Infections / Q000191:economics / Q000401:mortality / Q000517:prevention & control* / Q000635:transmission; D006801:Humans; D015994:Incidence; D008954:Models, Biological; D063065:Organophosphonates / Q000008:administration & dosage* / Q000627:therapeutic use; D015995:Prevalence; D013019:South Africa / Q000453:epidemiology; D000068698:Tenofovir; D014622:Vaginal Creams, Foams, and Jellies
chemical_list: D019380:Anti-HIV Agents; D063065:Organophosphonates; D014622:Vaginal Creams, Foams, and Jellies; D000068698:Tenofovir; D000225:Adenine