title: Optimal uses of antiretrovirals for prevention in HIV-1 serodiscordant heterosexual couples in South Africa: a modelling study.
abstract: BACKGROUND
  Antiretrovirals have substantial promise for HIV-1 prevention, either as antiretroviral treatment (ART) for HIV-1-infected persons to reduce infectiousness, or as pre-exposure prophylaxis (PrEP) for HIV-1-uninfected persons to reduce the possibility of infection with HIV-1. HIV-1 serodiscordant couples in long-term partnerships (one member is infected and the other is uninfected) are a priority for prevention interventions. Earlier ART and PrEP might both reduce HIV-1 transmission in this group, but the merits and synergies of these different approaches have not been analyzed.
  
  
  RESULTS
  We constructed a mathematical model to examine the impact and cost-effectiveness of different strategies, including earlier initiation of ART and/or PrEP, for HIV-1 prevention for serodiscordant couples. Although the cost of PrEP is high, the cost per infection averted is significantly offset by future savings in lifelong treatment, especially among couples with multiple partners, low condom use, and a high risk of transmission. In some situations, highly effective PrEP could be cost-saving overall. To keep couples alive and without a new infection, providing PrEP to the uninfected partner could be at least as cost-effective as initiating ART earlier in the infected partner, if the annual cost of PrEP is <40% of the annual cost of ART and PrEP is >70% effective.
  
  
  CONCLUSIONS
  Strategic use of PrEP and ART could substantially and cost-effectively reduce HIV-1 transmission in HIV-1 serodiscordant couples. New and forthcoming data on the efficacy of PrEP, the cost of delivery of ART and PrEP, and couples behaviours and preferences will be critical for optimizing the use of antiretrovirals for HIV-1 prevention. Please see later in the article for the Editors' Summary.
authors: Department of Infectious Disease Epidemiology, Imperial College London, United Kingdom. timothy.hallett@imperial.ac.uk
authors: Timothy B
authors: TB
authors: Hallett
authors: Jared M
authors: JM
authors: Baeten
authors: Renee
authors: R
authors: Heffron
authors: Ruanne
authors: R
authors: Barnabas
authors: Guy
authors: G
authors: de Bruyn
authors: Íde
authors: Í
authors: Cremin
authors: Sinead
authors: S
authors: Delany
authors: Geoffrey P
authors: GP
authors: Garnett
authors: Glenda
authors: G
authors: Gray
authors: Leigh
authors: L
authors: Johnson
authors: James
authors: J
authors: McIntyre
authors: Helen
authors: H
authors: Rees
authors: Connie
authors: C
authors: Celum
mesh_terms: D000293:Adolescent; D000328:Adult; D044966:Anti-Retroviral Agents / Q000627:therapeutic use*; D018791:CD4 Lymphocyte Count; D003198:Computer Simulation; D003362:Cost-Benefit Analysis; D005260:Female; D015658:HIV Infections / Q000188:drug therapy / Q000453:epidemiology / Q000517:prevention & control* / Q000635:transmission / Q000821:virology; D006679:HIV Seropositivity / Q000635:transmission*; D015497:HIV-1 / Q000472:pathogenicity; D007722:Health Knowledge, Attitudes, Practice; D020010:Heterosexuality; D006801:Humans; D008297:Male; D008875:Middle Aged; D008954:Models, Biological; D012309:Risk-Taking; D012747:Sexual Partners; D013019:South Africa / Q000453:epidemiology; D055815:Young Adult
chemical_list: D044966:Anti-Retroviral Agents