15-Nov-2011 - 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."
Funding: The authors thank The Wellcome Trust (fellowship to TBH), and the Bill & Melinda Gates Foundation
(grant support to all authors), the US National Institutes of Health (1R01MH095507-01), and the Qatar National Research Fund
(NPRP 08-068-3-024). No funding bodies had any role in study design, data collection and analysis, decision to publish, or
preparation of the manuscript.
Competing Interests: TBH has received consultancy fees from the Bill & Melinda Gates Foundation for work not
directly related to the present work. GPG has in the past been a consultant in the field of Human Papilloma Virus research to
Glaxo SmithKline and Merck, and has been a consultant in the field of stem cell transplantation to ViroPharma, but has no
conflicts of interest in the HIV field. All other authors have declared that no competing interests exist.
Citation: 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
Infectious Disease Epidemiology
Imperial College London
London W2 1PG
Contact: Clare Weaver
Public Library of Science