Mother-to-child transmission of HIV-1
Jacquez, J.A.
Journal of Acquired Immune Deficiency Syndromes and Human Retrovirology Official Publication of the International Retrovirology Association 16(4): 284-292
1997
ISSN/ISBN: 1077-9450 PMID: 9402076 DOI: 10.1097/00001432-199502000-00013Document Number: 270748
Based on a review of the literature on maternal-child HIV transmission, the author presents a stochastic model in which the probability of HIV transmission per week during pregnancy, parturition, and breast feeding is conceptualized as proportional to the mother's viral load at that stage. The model combines data on culturable virus levels and RNA copies in plasma as measures of maternal viral load. Through use of transmission data on women in the primary stage of infection, the probability of HIV transmission during pregnancy was calculated as a function of the time pregnancy starts in relation to the stage of infection. Also calculated was the conditional probability of transmission by breast feeding for 20 weeks, dependent on the infant escaping infection during pregnancy and delivery. Predicted transmission probabilities were quite low during the asymptomatic stage of maternal infection and highest when the mother was in the primary stage of infection or the late stages of the disease. RNA data emerged as a better basis for the calculations than culturable virus. The considerable variation by country in reported rates of maternal-child HIV transmission could be explained by changes in the mix of women in the primary, asymptomatic, and later stages of infection.