Reduction in overtreatment of gonorrhea and chlamydia through point-of-care testing compared with syndromic management for vaginal discharge: a modeling study for Zimbabwe

Background Zimbabwe’s national guidelines for STI management recommend that high-risk women presenting with vaginal discharge syndrome (VDS) are prescribed antibiotics for gonorrhea (NG), chlamydia (CT), trichomoniasis (TV), and bacterial vaginosis (BV). The performance of this approach depends on its clinical interpretation and implementation. Here, we investigate the potential relative impact of an NG/CT/TV point-of-care (POC) test on undertreatment, overtreatment and disease burden, in the context of different implementations of syndromic management of women with VDS. Methods We created an agent-based model with an age-risk-stratified sexual network and modeled co-circulation of NG, CT, and TV along with HIV and BV. We estimated symptomatic proportions and care-seeking rates under three different scenarios around the implementation of treatment guidelines, corresponding to all, most, or half of women being treated for NG + CT upon presentation with VDS. For each implementation scenario we estimated disease burden and over/undertreatment rates assuming continuation of the standard of care with/without a POC NG/CT/TV test available over 2027–2040. Results Under a treat-all interpretation of the syndromic management guidelines, we estimate that 70–80% of antibiotics for NG/CT would currently be given to women without these infections. Overtreatment would fall to < 5% if a sensitive POC test for NG/CT/TV were available. However, if the implementation of the guidelines implies that only half of women seeking care for VDS are treated, then a POC test would also reduce undertreatment and disease burden, with > 500k additional women correctly treated for NG and ~ 1.5m correctly treated for CT and TV, and 24%/15% reductions in the number of women with NG/CT by 2040. Conclusion Improved data on the functioning of syndromic management in practice would help refine the estimates of the health impact and the overall value proposition of a highly sensitive POC diagnostic for NG/CT/TV. However, even without such data, our analysis demonstrates the potential for such a diagnostic to reduce overtreatment by > 90% relative to plausible assumptions regarding the standard of care.