Objective: To describe the rationale and design of a randomized trial of the impact of improved services for the treatment of sexually transmitted diseases (STD) on the incidence of HIV infection in Mwanza Region, Tanzania.
Methods: The likely impact of improved STD treatment services on HIV incidence, and the need for empirical information on the effectiveness of this intervention strategy, are discussed. The rationale and design of such an intervention programme in Mwanza Region, and of a community-randomized trial to measure the impact of the programme on HIV and other STD, are presented. Problems in the design and interpretation of the trial are reviewed.
Results: Results of the baseline survey of the cohort of over 12,000 adults in 12 communities are presented in a companion paper.
Conclusion: There is an urgent need for effective preventive measures against the HIV epidemic in sub-Saharan Africa and other developing regions. Improved STD treatment has been promoted as a potentially effective strategy, but there is little empirical information on its impact. The trial in Mwanza Region is the first randomized study of this intervention and should provide valuable data for health policy makers.
PIP: Given the likelihood that other sexually transmitted diseases (STDs) act as co-factors in the sexual transmission of human immunodeficiency virus (HIV) in Africa, programs to improve the diagnosis and treatment of STDs may be an important component of acquired immunodeficiency syndrome (AIDS) control. To evaluate the impact of such a strategy, a randomized trial involving the integration of improved STD treatment into the existing primary health care system was initiated in Tanzania's Mwanza Region in late 1991. Program components include health personnel training, development of syndromic treatment algorithms, regular drug deliveries, supervisory visits to health facilities, and establishment of an STD reference clinic. The region's rural population was targeted due to its low yet increasing HIV prevalence, high prevalence of STDs, and amenability to a community-randomized study design. Twelve communities, defined as the population served by a health center and its satellite dispensaries, were selected for the trial and formed into six matched pairs on the basis of geographic area, HIV prevalence, and pre-existing levels of STD attendance. One set of communities was randomly selected to receive the intervention during the first year of the trial; the others will receive services at the end of the two-year follow-up period. Program outcome--defined as the incidence of HIV infection in intervention and control communities during the two-year follow-up--will be measured in a cohort of 12,000 randomly selected adults (1000 per community). This sample size offers a high power of detecting a halving of the annual HIV incidence rate from 1% to 0.5%.