Association between the Replication Capacity and Mother‐to‐Child Transmission of HIV‐1, in Antiretroviral Drug–Naive Malawian Women

Replication capacity and transmission of human immunodeficiency virus (HIV)–1 in antiretroviral drug–naive Malawian women who had subtype C infection were investigated. Infant children of these women received either 1 dose of nevirapine or 1 dose of nevirapine plus 1 week of daily doses of zidovudine. PhenoSense HIV was used to determine replication capacity in 49 women whose infants were infected with HIV-1 and in 47 women whose infants were uninfected by 6–8 weeks of age. Mean replication capacity was higher in transmitters than in nontransmitters (P=.01). In a multivariate model, higher replication capacity was associated with transmission (odds ratio, 1.45 for each 10% increase in replication capacity [95% confidence interval, 1.11–1.90]; P = .0063), after adjustment for maternal HIV-1 load and other factors