In sub-Saharan Africa, couples in long-term relationships where one partner is HIV-positive and the other is HIV-negative (HIV serodiscordant couples) could benefit from anti-AIDS drugs (antiretroviral therapy) given either as treatment or as a prevention measure (prophylaxis) to reduce the risk of HIV transmission. These findings, from a modelling study led by Timothy Hallett from Imperial College London and published in this week's PLoS Medicine, also show that this strategy could be cost-effective.
In sub-Saharan Africa, where most new HIV infections occur and condom use is often low, 10% of stable partnerships are serodiscordant. The authors used detailed information and specific data from South Africa to construct a model to simulate HIV infection and disease progression among hypothetical HIV serodiscordant couples in stable heterosexual relationships. The authors used the model to compare the impact on HIV transmission, survival and quality of life and the cost-effectiveness of different prophylaxis strategies.
To keep couples alive without the HIV-uninfected partner becoming infected, the authors found that it could be at least as cost-effective to provide prophylaxis to the uninfected partner as to initiate antiretroviral therapy earlier than current guidelines in the infected partner. Specifically, the most cost-effective strategy for couples could be to use prophylaxis in the uninfected partner prior to starting antiretroviral therapy in the infected partner.
These findings suggest that prophylaxis may become a valuable addition, in some settings, to existing approaches for HIV prevention such as condom promotion, male circumcision programs and anti-retroviral treatment.
The authors say: "We hope [these findings] might inform the choices that will be available for HIV prevention in couples. We note, however, that it is important that many other considerations besides cost effectiveness should inform decision-making for HIV treatment initiation and provision of [prophylaxis] in couples, including equitable access and the preferences of the couples themselves."
Hallett TB, Baeten JM, Heffron R, Barnabas R, de Bruyn G, et al. (2011) Optimal Uses of Antiretrovirals for Prevention in HIV-1 Serodiscordant Heterosexual Couples in South Africa: A Modelling Study. PLoS Med 8(11): e1001123. doi:10.1371/journal.pmed.1001123