Interventions that target individuals with a high risk of contracting HIV have a negligible impact on HIV transmission in the general population, according to a new study of communities in Zimbabwe, published today. The three-year study shows that community-based peer education, free condom distribution, and clinic-based STI treatment and counselling services targeted at female sex workers and their male clients had no impact on HIV incidence in the wider community.
The study shows that it was possible to reduce the incidence of HIV in men - but not the women - who were reached by the programme. However, the reduction in HIV incidence amongst these men did not have the anticipated impact on HIV incidence in the larger community.
The researchers, writing in the journal PLoS Medicine, had hoped that levels of HIV in the community as a whole could be reduced through targeting men and women who were perceived to have the riskiest sexual behaviour and reducing the incidence of HIV amongst them. They believed that this would reduce HIV incidence in the wider sexual networks where these people were thought to be key.
The programme aimed to reduce transmission through sex workers and it provided women with small interest-free loans together with training in small business management, in order to reduce their economic dependence on sex work. Recent studies show that commercial sex work centred around bars and beer halls remains a major source of HIV transmission.
The male participants benefited from the programme with a decrease in incidence of HIV-1, a reduction in reporting of unprotected sex with casual partners, and a decrease in symptoms of sexually transmitted infections. However, the study found that these benefits were not shared by the sex workers reached by the programme and there was no resultant reduction in HIV incidence for the community as a whole.