Objective: To examine the relationships between maternal knowledge and concern about HIV status, adoption of preventive practices and risk of acquiring HIV in Zimbabwe.
Methods: Knowledge and behavioural data were collected via interview from 2595 mothers enrolled in ZVITAMBO, a randomized trial of postpartum vitamin A supplementation that also offered education on safer infant feeding and sexual practices. Mothers were tested for HIV at delivery; those uninfected at baseline were retested during study follow-up. Logistic regression methods were used to identify variables associated with adoption of preventive behaviours and, for HIV-negative mothers, their relationship to risk of acquiring HIV post-delivery.
Results: A total of 518 mothers (20%) reported practicing safer sex and 289 mothers (11%) reported modifying their feeding behaviour because of HIV. Fear of transmitting HIV (50.4%) and protecting the baby's health (30.9%) were the most frequently cited reasons for behaviour change. Forty-nine HIV-negative mothers acquired HIV during the first postpartum year. After taking into account other significant covariates, mothers who were concerned about their own HIV status were 1.9 times more likely (95% CI: 1.05-3.52; P = 0.03), and those reporting safer sex practices were 58% less likely to become infected (adjusted odds ratio: 0.42; 95% CI: 0.17-1.04; P = 0.06). Married women who reported practicing abstinence to prevent HIV were 3.2 times more likely to become infected than non-abstaining mothers (P = 0.01), while there were no new HIV infections among abstaining single mothers.
Conclusions: Greater emphasis should be given to safer sex practices among women who test negative in mother-to-child HIV prevention programmes.