In urban Zambia and Rwanda, heterosexual HIV transmission in both men and women takes place within marriage or cohabitation, according to an Article released on June 26, 2008 in The Lancet. As a result, public policy should promote couples’ testing and counseling as well as other evidenced-based interventions.

Significant rates of HIV infection have been well documented in sub-Saharan Africa, and the high frequency is often attributed to heterosexual transmission. The study, led by Dr Kristin Dunkle, Rollins School of Public Health, Emory University, Atlanta, GA, USA, and colleagues across Zambia and Rwanda, attempted to analyze the levels of HIV transmission within marriages, to assess if HIV-prevention methods should continue to focus on abstinence and non-marital sex.

Population data was taken regarding heterosexual behavior in the Demographic Health Surveys in Zambia between 2001 and 2002, and Rwanda in 2005. This was combined by the team with HIV joint status data of married or cohabiting couples and non-cohabiting couples in Lusaka, Zambia, and Kigali, Rwanda. Data was acquired from 1739 Zambian women, 540 Zambian men, 1176 Rwandan women, and 606 Rwandan men.

Using this information, they estimated the propability that an individual would acquire HIV infection from a cohabiting or non-cohabiting partner, and the likely total proportion of heterosexual HIV transmission that occurs between married or cohabiting couples each year. By modeling the data, it was estimated that 55-93% of new heterosexually acquired HIV infections in these settings probably occur within married or cohabiting couples, with slight variations between gender and country. When the model was extended to include the higher rates of condom use that are reported in non-cohabiting partners, this implied that the new heterosexually acquired HIV infections in marital or cohabiting couples would be 60-94% higher.

The transmission of HIV in non blood-related couples who are both naive of their HIV status is estimated to be 20% per year. An intervention for these couples, which has previously reduced transmission in cohabiting couples from 20% to 7% each year in Zambia, could prevent between 36% and 60% of heterosexually transmitted HIV infections that might otherwise occur.

In conclusion, the authors state that new policy should be instated to now focus on married and cohabiting heterosexual partners. “Since most heterosexual HIV transmission for both men and women in urban Zambia and Rwanda takes place within marriage or cohabitation, voluntary counselling and testing for couples should be promoted, as should other evidence-based interventions that target heterosexual couples.”

Dr Rebecca Bunnell, Global AIDS Program, Centers for Disease Control and Prevention-Kenya, Nairobi, Kenya and Dr Peter Cherutich, National AIDS/STD Control Programme, Ministry of Health, Nairobi, Kenya, contributed an accompanying comment, in which they call policy makers to arms regarding this data: “The findings by Dunkle and colleagues are an urgent call to governments and programmes for HIV prevention, care, and treatment throughout the continent to truly scale up HIV testing with an emphasis on couples and a goal of universal coverage. Definition, standardisation, and implementation of a complete package for efficacious couple-based interventions for all types of couples for HIV prevention and care, including antiretroviral therapy and circumcision, will further decrease HIV transmission within the largest population group at risk within sub-Saharan Africa.”

New heterosexually transmitted HIV infections in married or cohabiting couples in urban Zambia and Rwanda: an analysis of survey and clinical data
Kristin L Dunkle, Rob Stephenson, Etienne Karita, Elwyn Chomba, Kayitesi Kayitenkore, Cheswa Vwalika, Lauren Greenberg, Susan Allen
Lancet 2008; 371: 2183-91
Click Here For Journal

Universal HIV testing and counselling in Africa
Rebecca Bunnell, Peter Cherutich
Lancet 2008; 371: 2149-50
Click Here For Journal

Written by Anna Sophia McKenney