Couples at risk: HIV-1 concordance and discordance among sexual partners receiving voluntary counseling and testing in Uganda.

Objective: To determine correlates of HIV-1 concordance for couples receiving voluntary HIV counseling and testing.

Design: Cross-sectional study of couples receiving voluntary HIV counseling and testing in Kampala, Uganda.

Methods: An interview and physical examination were conducted for 49 HIV-1-concordant (both partners infected with HIV) and 126 HIV-1-discordant (1 partner infected with HIV and 1 partner HIV negative) couples. Blood samples from all participants were tested for HIV-1 and syphilis serology. CD4 cell count and HIV load were characterized for all HIV-infected persons. Urine samples were tested for Neisseria gonorrhoeae and Chlamydia trachomatis using ligase chain reaction. Associations between couples' HIV status and key sociodemographic, behavioral, and biomedical factors were analyzed.

Results: Men in HIV-concordant couples were more likely than men in HIV-discordant couples to be living together with their sexual partner (odds ratio [OR], 11.3; 95% confidence interval [CI], 2.8-53.7; P=0.004), to be uncircumcised (OR, 4.5; 95% CI, 1.1-18.8; P=0.042), and to have higher HIV loads (OR for each log increase, 3.0; 95% CI, 2.0-4.7; P<0.001). Women in HIV-concordant couples were more likely than women in HIV-discordant couples to be living together with their sexual partner (OR, 19.0; 95% CI, 3.8-84.8), to have an uncircumcised male partner (OR, 6.5; 95% CI, 1.6-26.4), to have had a sexually transmitted disease in the 6 months before enrollment (OR, 1.9; 95% CI, 0.9-4.5), and to have higher HIV loads (OR for each log increase, 2.2; 95% CI, 1.5-3.2).

Conclusions: Several behavioral and biologic risk factors were associated with HIV concordance for couples. Providing early sexually transmitted disease diagnosis and treatment, antiretroviral therapy, and specially designed counseling to HIV-discordant couples may help prevent HIV transmission in couples where being in a stable sexual relationship is a major risk factor for HIV infection.