Cost-effectiveness of improved treatment services for sexually transmitted diseases in preventing HIV-1 infection in Mwanza Region, Tanzania

Background. A community-randomised trial was undertaken to assess the impact, cost, and cost-effectiveness of averting HIV-1 infection through improved management of sexually transmitted diseases (STDs) by primary-health-care workers in Mwanza Region, Tanzania. Methods. The impact of improved treatment services for STDs on HIV-1 incidence was assessed by comparison of six intervention communities with six matched communities. We followed up a random cohort of 12,537 adults aged 15-54 years for 2 years to record incidence of HIV-1 infection. The total and incremental costs of the intervention were estimated (ingredients approach) and used to calculate the total cost per case treated, the incremental cost per HIV-1 infection averted, and the incremental cost per disability-adjusted life-year (DALY) saved. Findings. During 2 years of follow-up, 11,632 cases of STDs were treated in the intervention health units. The baseline prevalence of HIV-1 infection was 4%. The incidence of HIV-1 infection during the 2 years was 1.16% in the intervention communities and 1.86% in the comparison communities. An estimated 252 HIV-1 infections were averted each year. The total annual cost of the intervention was US$59 060 (1993 prices), equivalent to $0.39 per head of population served. The cost for STD case treated was $10.15, of which the drug cost was $2.11. The incremental annual cost of the intervention was $54,839, equivalent to $217.62 per HIV-1 infection averted and $10.33 per DALY saved (based on Tanzanian life expectancy) or $9.45 per DALY saved (based on the assumptions of the World Development Report). In a sensitivity analysis of factors influencing cost-effectiveness, cost per DALY saved ranged from $2.51 to $47.86. Interpretation. Improved management of STDs in rural health units reduced the incidence of HIV-1 infection in the general population by about 40%. The estimated cost-effectiveness of this intervention ($10 per DALY) compares favourably with that of, for example, childhood immunisation programmes ($12-17 per DALY). Cost-effectiveness should be further improved when the intervention is applied on a larger scale. Resources should be made available for this highly cost-effective HIV control strategy.