Adoption of safer infant feeding and postpartum sexual practices and their relationship to maternal HIV status and risk of acquiring HIV in Zimbabwe.

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.

HIV-1 and HIV-2 prevalence and associated risk factors among postnatal women in Harare, Zimbabwe.

Studies of antenatal women form the predominant source of data on HIV-1 prevalence in Africa. Identifying factors associated with prevalent HIV is important in targeting diagnostic services and care. Between November 1997 and January 2000, 14,110 postnatal women from Harare, Zimbabwe were tested by ELISAs reactive to both HIV-1 and HIV-2; a subset of positive samples was confirmed with assays specific for HIV-1 and HIV-2. Baseline characteristics were elicited and modelled to identify risk factors for prevalent HIV infection. HIV-1 and HIV-2 prevalences were 32.0% (95% CI 31.2-32.8) and 1.3% (95% CI 1.1-1.5), respectively; 4% of HIV-1-positive and 99% of HIV-2-positive women were co-infected. HIV-1 prevalence increased from 0% among 14-year-olds to >45% among women aged 29-31 years, then fell to <20% among those aged>40 years. In multivariate analyses, prevalence increased with parity, was lower in married women than in single women, divorcees and widows, and higher in women with the lowest incomes and those professing no religion. Adjusted HIV-1 prevalence increased during 1998 and decreased during 1999. Age modified the effects of parity, home ownership and parental education. Among older women, prevalence was greater for women who were not homeowners. Among younger women, prevalence increased with parity and low parental education. None of these factors distinguished women co-infected with HIV-2 from those infected with HIV-1 alone. Prevalent HIV-1 infection is associated with financial insecurity and weak psychosocial support. The ZVITAMBO study apparently spanned the peak of the HIV-1 epidemic among reproductive women in Harare.