Evaluation of Presumptive Periodic Treatment (PPT) of Sexually Transmitted Infections (STIs)

Overview

Sexually transmitted infections (STI) are important causes of reproductive health morbidity and mortality, and have long been implicated as major co-factors in the sexual transmission of HIV. Both ulcerative and non-ulcerative STI have been found to be strongly associated with HIV in cross-sectional and prospective studies and hence STI prevention and care are important aspects of HIV prevention. Periodic Presumptive Treatment of STIS (PPT) where risk populations are presumptively treated with a single dose of Azithromycin+Cefixime in regular intervals of 3 months has been shown to be effective in reducing STI prevalence at population level and has recently been integrated into the National STI guidelines of Tanzania. The USAID funded Sauti program will be one of the first to implement these new guidelines and roll out PPT in high risk populations in selected regions in Tanzania. This study will evaluate the impact of PPT as delivered by the Sauti program on prevalence of STIs in men who have sex with men and female sex workers in Dar es Salaam and Shinyanga respectively.

This intervention linked study evaluates the impact of PPT on population level in FSW and MSM in Tanzania (Shinyanga and Dar es Salaam respectively). It is expected that PPT will reduce laboratory diagnosed STIs by 50% in the population after a roll out of 6 months. This evaluation uses a cross-sectional venue-based sampling design. Three rounds of cross sectional data collection will be undertaken for MSM in Dar es Salaam and FSW in Shinyanga at three months intervals (baseline, 3 months and 6 months). The change in prevalence will be measured between baseline and 6 months assessments. The interim assessment will be used to refine the sample size. Study participants will be recruited in venues frequented by FSW (Shinyanga) and MSM (Dar es Salaam) in wards where Sauti operates. Respondents will be continuously sampled from all venues until sample size is reached. In each round of data collection, study participants will undergo physical examination, biological specimen collection, laboratory and HIV tests and a questionnaire. STI prevalence in MSM and FSWs will be measured during each survey and laboratory-confirmed STI prevalence (gonorrhoea, chlamydia, syphilis) will be assessed. Additionally, effect on STI prevalence in the bridge population will be measured by retrospective analysis of routine data for the prevalence of syndromic STIs among the mining population in Shinyanga, as collected in the context of the Sauti program mobile biomedical services (CBHTC+), which will visit the major mines in Shinyanga prior PPT implementation and after each survey. By the term major mines, we mean mines with large population of male mine workers (between 1000-2000 male mine workers) at higher risk of HIV rather than mines with modern mining infrastructure.