Lessons for management of sexually transmitted infection treatment programs as part of HIV/AIDS prevention strategies.

We analyzed the treatment schedule of a long-running HIV/AIDS prevention program in Managua, Nicaragua, that targets sex workers through mass and specific clinic-based treatment of sexually transmitted infections and confirmed the role of frequency of treatment in generating a sustained reduction in measured prevalence of sexually transmitted infections. Unplanned variations in the time between treatments, a situation common to public health programs, provided the basis for attributing changes in measured levels of sexually transmitted infections to the program and for testing the statistical significance of the relationship. This information is critical to program design and funding and to resource allocation.