Individual, Partner, and Couple Predictors of HIV Infection among Pregnant Women in Malawi: A Case-Control Study.

We aimed to understand drivers of HIV-infection in pregnant women in Malawi. The study was conducted in antenatal and labor and delivery wards. HIV-infected women and their partners (cases) were frequency matched in a 1:2 ratio based on age and screening location to HIV-uninfected women and their partners (controls) in a prevalent case-control study. Characteristics associated with female HIV infection were assessed using logistic regression modeling. At screening, HIV-infected women were more likely to have partners outside Lilongwe than HIV-uninfected women (24% vs. 0%, p < 0.0001). Case females were more likely to have HIV-infected study partners than control females (75% vs. 4%, p < 0.0001). The odds of female HIV-infection were higher if either couple member reported ≥ 2 lifetime marriages (OR 9.0, CI 2.6-30.9) or ≥ 3 lifetime partners (OR 18.0, CI 3.1-103.6) and lower if either reported past couple HIV testing and counseling (OR 0.1, CI 0.04-0.3). Targeting women with migrating partners, promoting couple HIV testing and counseling, and limiting partners could slow HIV transmission.