Thirty-two studies with 53,951 participants were included.
Out of the 32 studies identified, 25 reported decreases in sexual transmission following the intervention.
Social cognitive programmes: the interventions were delivered in small groups or individually. In clinics treating people with STD, each study reported significant reductions in HIV risk acts; three found reductions in STD rates. The ethnicity of the participants influenced the outcomes of the interventions. Interventions with intravenous drug users were more successful in changing the substance misuse behaviour rather than sexual behaviours. Needle cleaning and needle sharing behaviours showed the most consistent change. Interventions in persons with severe mental illness reported success with small group programmes over multiple sessions. A community-based intervention found that over 24 months there were reductions of 40 and 50% in the incidence of STDs and HIV, respectively.
Treatment for STDs: a large trial in Mwanai Tanzania demonstrated a 42% reduction in HIV incidence over 2 years in villages randomly assigned to a comprehensive STD intervention, although no changes in sexual risk behaviours were observed.
Pre- and post-test counselling: HIV testing and counselling appeared to be an efficacious strategy, particularly for seropositive adults, in reducing unprotected sex and other risk behaviours and in increasing partner communication.