Mwanza trial

The first large randomised controlled trial of using STI treatment to control HIV infection produced a promising result in 1995 - a 42% reduction in HIV incidence.¹

In the rural Mwanza province of Tanzania, south of Lake Victoria, Grosskurth and colleagues compared HIV incidence in twelve communities of around 1000 people each, aged 15 to 54.

Six communities received health education about STIs, regular check-ups at a dedicated STI clinic and prompt treatment for any symptoms. The other six matched control groups did not receive the intervention. The total length of the study was two years and retention was 71%, so that 8845 of the cohort were seen at the final visit.

Baseline HIV prevalences were 3.8% and 4.4% in the intervention and comparison communities. Of those initially HIV-negative, 48 out of 4149 (1.2%) became infected with HIV in the intervention groups and 82 out of 4400 (1.9%) in the comparison communities. HIV incidence was consistently lower in all six intervention communities. The estimated reduction in the risk of contracting HIV conferred by STI treatment was 42%. No change in sexual behaviour was reported in either group, so the STI treatment appeared solely responsible for the reduced HIV incidence.

This seemed very good news: relatively easily affordable STI treatment, used only when needed, appeared to have a promising role in reducing HIV in African communities stricken by the virus.