Natural History and Risk Factors Associated with Early and Established HIV Type 1 Infection among Reproductive‐Age Women in Malawi
1College of Medicine, University of Malawi, Chichiri, and 2Johns Hopkins University–University of Malawi College of Medicine Research Project, Blantyre, Malawi; and 3Bloomberg School of Public Health, Johns Hopkins University, Baltimore, Maryland
Background.
Data evaluating the biological events and determinants of early human immunodeficiency virus type 1 (HIV‐1) infection are limited in sub‐Saharan Africa. We examined plasma viral levels and trends during early and established HIV‐1 infection among reproductive‐age women who participated in a randomized trial to treat genital tract infection in Malawi. We also assessed the association of injectable hormonal contraceptive use with HIV‐1 infection.
Methods.We studied 3 groups of women who were infected or uninfected with HIV‐1: seroconverters, seroprevalent women, and seronegative women. Questionnaires and blood samples were collected at baseline and every 3 months for 1 year. The virus set point in seroconverters and levels and trends of viral load over time were determined. The associations of injectable hormonal contraceptive use with HIV‐1 infection and viral load were assessed using conditional logistic regression and mixed‐effect models, respectively.
Results.In the original clinical trial, 844 women infected with HIV‐1 and 842 women not infected with HIV‐1 were enrolled. Of 31 women who experienced seroconversion during 12 months, 27 were matched with 54 seroprevalent and 54 seronegative women. The estimated median plasma virus set point was 4.45 log10 copies/mL (interquartile range, 4.32–5.14 log10 copies/mL). Injectable hormonal contraceptive use was significantly associated with HIV‐1 seroconversion (adjusted odds ratio, 10.42; 
) but not with established HIV‐1 infection. Among the seroconverters, a statistically significant interaction was found between the linear association of viral load and time of injectable hormonal contraceptive use (regression coefficient, −0.14; 
).
Conclusion.Knowledge of virus set point and trends of viral load in HIV‐1 seroincident and seroprevalent asymptomatic women could assist in antiretroviral treatment management.
Received 26 September 2007; accepted 23 January 2008; electronically published 5 May 2008.