Objectives: To determine the mother-to-child transmission (MTCT) rate of HIV-1 and to compare the survival patterns among infants born to HIV-1 infected and seronegative mothers.
Design: A two year prospective study from 1991 to 1995.
Methods: 345 HIV-1 infected mothers and 351 seronegative mothers and their infants were examined at regular intervals up to 24 months of age.
Results: The intermediate estimate of MTCT rate of HIV-1 was found to be 31.9%; (95% confidence interval (CI) 26.9 to 37.1). Of infants born to HIV-1 infected mothers 17% died compared with 2% of infants born to seronegative mothers. Forty six (43%) of the 107 HIV-1 infected infants died compared with 16 (219%) of the 559 uninfected infants. In a multivariate analysis, risk factors independently associated with infant mortality were low birth weight (hazard ratio (HR) 2.80; CI 1.52 to 5.13), HIV infected infant (HR 10.50; CI 5.48 to 20.15), HIV infected mother (HR 3.23; CI 3.17 to 15.85) and maternal death (HR 2.77; CI (1.09 to 7.06).
Conclusion: The estimated MTCT rate of HIV-1 is comparable with rates of 25% to 45% reported from the African region. The poor survival of HIV-1 infected infants indicates the necessity for effective and comprehensive HIV/AIDS control strategies in Zimbabwe.