(P259) Characterising the spatiotemporal burden of symptomatic sexually transmitted infections in Malawi

Background: Aetiologic prevalence surveys are the preferred data to assess sexually transmitted infection (STI) burden but are limited or incomplete in many countries. Representative household surveys evaluating self-reported STI symptoms and syndromic case reporting are more readily available but underutilized for surveillance. We therefore evaluated the consistency of relative burden of symptomatic STIs measured through household survey self-reporting and health facility case reporting in Malawi.

Methods: We analysed data on self-reported STI symptoms and treatment seeking in the past 12 months among ever sexually active adults from four Demographic and Health Surveys in Malawi between 2000 and 2015. We used generalised linear mixed-effects models to identify trends, spatial variation across districts, and sociodemographic determinants. We compared self-reported symptoms to syndromic diagnoses recorded in facility-level aggregate STI case reports in the Malawi Health Management Information System between 2014 and 2021. The prevalence of self-reported treated STI symptoms and the annual incidence of diagnoses were calculated using census population projections.

Results: Between 2000 and 2015, 11.0% (95% CI:10.7-11.4%) of ever sexually active adults reported having an STI or STI symptom in the past year, of whom 54% (95% CI:53-56%) reported seeking care for their last infection. From household surveys, the estimated proportion who sought treatment in the past year was 3.8% (95% CI:2.2-6.6%) for genital ulcer, 3.7% (95% CI:1.9-7.2%) for vaginal discharge, and 2.5% (95% CI:1.9-7.2%) for urethral discharge. Comparatively, the mean annual diagnosis rates reported by health facilities were 0.5% for genital ulcer disease, 2.2% for vaginal discharge syndrome, and 2.0% for urethral discharge syndrome. Temporal trends were not significant for self-reported symptoms, whereas annual diagnosis rates for vaginal discharge and urethral discharge, but not genital ulcer, increased over time. The burden of both self-reported STI symptoms and syndromic case reports was highest among women and in Southern Malawi.

Conclusions: Two sources of data on symptomatic STIs in Malawi were generally inconsistent in magnitude but had complementary trends with the burden of HIV. Future efforts should triangulate available aetiologic data with symptom reporting to further evaluate the use of household surveys to supplement and strengthen STI surveillance.