Official websites use. Share sensitive information only on official, secure websites. We conducted a systematic review and meta-analysis of observational studies of the risk of HIV-1 transmission per heterosexual contact. The search to September identified 43 publications based on 25 different study populations.
In meta-regression analysis, the infectivity across estimates in absence of CS work was significantly associated with gender, setting, the interaction between setting and gender and HIV prevalence. Study estimates among non-circumcised men were at least twice those among circumcised men.
Developing country estimates were more heterogeneous than developed country estimates, which indicates poorer study quality, greater heterogeneity in risk factors or under-reporting of high-risk behaviour. Efforts are needed to better understand these differences and quantify infectivity in developing countries.
Since the beginning of the HIV epidemic, mother-to-child transmission and iatrogenic transmission through contaminated blood products and unsafe injections have decreased due to improved health procedures and treatment options, especially in developed countries 1 - 5. Some believe that sexual transmission has been overestimated, while iatrogenic transmission has been underestimated 10 - Quantifying the risk of HIV infection following sexual intercourse with an infected partner is important to better understand the epidemiology of HIV infection worldwide and to take appropriate public health decisions.
Sexual transmission estimates fall broadly into two categories: per-act transmission probabilities 13 - 23 , which quantify the risk of infection per sexual contact, and per-partner transmission probabilities 13 , 24 - 27 , which measure the cumulative risk of infection over many sex acts during a partnership.
