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

BACKGROUND: (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- and risk-stratified sexual network and modelled 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 less than 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 >500 000 additional women correctly treated for NG and ~1.5 million 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.