Vaccine and Infectious Disease Division

HIV discordancy in sub-Saharan Africa

Diagram illustrating the possible combination of HIV statuses within partnerships.

Understanding how HIV is transmitted in different populations is important to preventing this deadly infection’s spread, but this information is not always readily available. Many studies that categorize HIV infection rates are unable to ascertain how the individuals became infected. Serodiscordant couples, long-term marriages or partnerships where one partner is HIV positive and the other is not, offer a chance to both better understand and prevent HIV transmission. VIDD affiliate investigator Dr. Laith Abu-Raddad and colleagues performed statistical analyses on data from the Demographic and Health Survey to assess the numbers and proportions of HIV serodiscordant couples in 20 countries in sub-Saharan Africa.

The researchers found that in countries where HIV is very prevalent, many long-term partnerships are affected by HIV and about half of these are serodiscordant. In countries where HIV is less common, fewer partnerships are affected by HIV but the majority of these partnerships are HIV serodiscordant. The scientists’ analyses showed that at least half of this variability in HIV discordancy is due to differences in HIV prevalence in these different communities. Many HIV prevention tactics are aimed at HIV discordant couples, but the researchers’ findings indicate that identifying such partnerships and evaluating the impact of such interventions may be challenging.

Chemaitelly H, Cremin I, Shelton J, Hallett TB, Abu-Raddad LJ. Distinct HIV discordancy patterns by epidemic size in stable sexual partnerships in sub-Saharan Africa. Sex Transm Infect. 2012 Feb;88(1):51-7.