Cluster randomized trials (CRT) are often used to evaluate therapies or interventions in
situations where individual randomization is not possible or not desirable for logistic …

More than 42 million people worldwide are now infected with HIV, in spite of sustained
prevention activities. Although the spread of HIV has been primarily sexual, epidemiological …

Background and Methods We examined the influence of viral load in relation to other risk
factors for the heterosexual transmission of human immunodeficiency virus type 1 (HIV-1). In …

Cluster Randomised Trials, Second Edition discusses the design, conduct, and analysis of
trials that randomise groups of individuals to different treatments. It explores the advantages …

Born Too Soon: The Global Action Report on Preterm Birth features the first-ever estimates
of preterm birth rates by country and is authored by a broad group of 45 international multi …

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 …

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 …

Mathematical models are increasingly being used to examine questions in infectious
disease control. Applications include predicting the impact of vaccination strategies against …

Objectives: To assess and summarize the published literature on the extent to which
bacterial vaginosis may increase the risk of HIV acquisition. Design: Meta-analysis of …

Background Increased rates of sexually transmitted infections (STIs) have been reported
among men who have sex with men. We aimed to assess whether post-exposure …