Abstract (See the editorial commentary by Gray and Wawer on pages 351–2.) Background.
Knowledge of factors that affect per-act infectivity of human immunodeficiency virus type 1 …

Background We estimated rates of human immunodeficiency virus (HIV)–1 transmission per
coital act in HIV-discordant couples by stage of infection in the index partner Methods We …

Studies of cumulative HIV incidence suggest that cofactors such as genital ulcer disease,
HIV disease stage, and male circumcision influence HIV transmission; however, the …

Background The risk of sexual HIV transmission in serodiscordant couples when the HIV-
positive partner has full virologic suppression on combination antiretroviral therapy (cART) is …

Background: Effective HIV prevention programs rely on accurate estimates of the per-act risk
of HIV acquisition from sexual and parenteral exposures. We updated the previous risk …

Objectives: To measure HIV-1 discordance among migrant and non-migrant men and their
rural partners, and to estimate the relative risk of infection from inside versus outside primary …

Background Understanding the absolute and relative risk of human immunodeficiency virus
type 1 (HIV) acquisition during pregnancy and the postpartum period can inform HIV …

Background The probability of HIV-1 transmission per coital act in representative African
populations is unknown. We aimed to calculate this probability overall, and to estimate how …

We did a systematic review and meta-analysis of observational studies of the risk of HIV-1
transmission per heterosexual contact. 43 publications comprising 25 different study …

Background: Recent studies have estimated the reduction in HIV-1 infectiousness with
antiretroviral therapy (ART), but high-quality studies such as randomized controlled trials …