A prospective study of vertical transmission of HIV-2 in Bissau, Guinea-Bissau

Objectives: To determine the vertical transmission rate of HIV-2 and clinical findings associated with vertically transmitted HIV-2 infection. Design: A prospective study of HIV-2 transmission in children of HIV-2-seropositive mothers, and a comparison of clinical findings between children of seropositive and seronegative mothers. Setting: Recruitment of women delivering at the national hospital in Bissau, Guinea-Bissau. Follow-up by home visits. Subjects and methods: Eighty-six newborns of 82 HIV-2-seropositive mothers and a control group of 102 newborns of HIV-seronegative mothers were followed-up clinically and by HIV serology until the children reached the age of 20 months. Results: Of the 86 children of seropositive mothers, 51 had a complete follow-up, 22 died and 13 were lost due to change of residence. Of the 102 children of seronegative mothers, 63 had a complete follow-up, 13 died and 26 were lost due to change of residence. None of 51 children of seropositive mothers had serological evidence of HIV-2 infection at the end of the follow-up period. There was no significant difference in the frequency of clinical symptoms between the children in the study group and the children in the control group. The mortality during the first year of life was not significantly different between the children of seropositive and seronegative mothers (13 out of 80 and 11 out of 94, respectively, P >0.05, excluding children lost to follow-up). Only three of the dead children of seropositive mothers and one of the dead children of seronegative mothers had any symptoms that might be related to HIV-2 infection (diarrhoea > 1 month). Conclusion: Vertical transmission of HIV-2 appears to be rare.