Preventing sexually transmitted diseases may not reduce HIV risk
BMJ 1999; 318 doi: https://doi.org/10.1136/bmj.318.7182.486 (Published 20 February 1999) Cite this as: BMJ 1999;318:486
A Ugandan project designed to prevent sexually transmitted diseases (STD) has shown no reduction in the risk of HIV-1 transmission, according to results published last week that conflict with previous studies.
Researchers working in the Rakai district of Uganda randomly assigned 10 community clusters of people negative for HIV-1 either to an active intervention group given intensive home based antibiotic treatment for controlling sexually transmitted disease or to a placebo group receiving low dose vitamins and minerals. At enrolment, the prevalence rates of sexually transmitted diseaseswere similar for both groups. After 20 months, the prevalence rates of syphilis and trichomoniasis were significantly lower in the intervention group than in the placebo group (6%v 7%for syphilis; 9%v 14%for trichomoniasis). In contrast, the incidence of HIV-1 infection was the same in both groups-1.5 per 100 person years (Lancet 1999;353:525-35).
Researcher Maria Wawer, from the Center for Population and Family Health at Columbia UniversitySchool of Public Health, New York, commented: “We observed no effect of the STD intervention on the incidence of HIV-1 infection. In the Rakai population, a substantial proportion of HIV-1 acquisition appears to occur independently of treatable STD cofactors.”
In all, 6602 HIV-1 negative people aged 15-59 years were enrolled in the interventiongroup and 6124 in the placebo group. The baseline prevalence of HIV-1 in the communities studied was 16%The intervention group was treated with azithromycin (1000 mg single dose), ciprofloxacin (250 mg single dose) and metronidazole (2.0 g single dose). The pla-cebo group was offered an anthelmintic (mebendazole 100 mg, two doses), an iron folate tablet, and low dose multivitamins. Nearly three quarters of the participants (75%of the intervention group and 73%of theplacebo group) provided at least one follow up sample for HIV-1 testing.
The lack of effect of the Rakai control programme on HIV-1 transmission surprised the researchers, as another trial in 1995 suggested that sexually transmitted diseases enhance transmission of HIV-1 and that strategies to prevent them help to limit such transmission. The 1995 trial-carried out in Mwanza, Tanzania-showed that a strategy of more intensive diagnosis and treatment of sexually transmitted diseases reduced the incidence of HIV-1 infection by about 40%(Lancet 1995;346:530-6;1159-60).
