MOTHER-TO-CHILD TRANSMISSION OF HIV-1 IN CONGO, CENTRAL-AFRICA

Objective: To assess the risk of mother-to-child transmission of HIV-1 in a central African population and to study maternal factors associated with perinatal transmission. Design: Prospective cohort study of infants born to HIV-1-positive women and controls born to HIV-1-negative women enrolled sequentially in two prenatal clinics and one maternity hospital in Brazzaville, Congo. Subjects and methods: A total of 118 exposed and 208 control infants were followed from birth for at least 2 years. Assessment of infection in children and computation of transmission rate were made according to the European Economic Community/World Health Organization Ghent guidelines (1992). Results: The transmission rate was 40.4% [95% confidence interval (CI), 30.7-50.1]. Maternal age, parity, history of adverse pregnancy outcome or history of deceased children were not associated with transmission. However, independently, women whose relationship with their infant's father was less than 1 year, or women who had symptoms of HIV-1 during pregnancy had an increased risk of transmission [adjusted odds ratios, 11.1 (95% CI, 2.4-50.2) and 10.3 (95% CI, 2.9-37.1), respectively]. Conclusion: The transmission rate observed in Congo is in the upper range of the rates reported in Africa. The uneven distribution of cofactors for perinatal transmission, such as the presence of symptoms of HIV disease during pregnancy, may explain some of the variation observed across studies.