Mathematical modelling and health economics for the role of diagnostic strategies in the control and prevention, clinical management, and elimination of infectious diseases

In resource-limited settings the critical infrastructure necessary to support laboratory-based diagnostics may be absent, necessitating point-of-care tests (POCTs). Mathematical and health economics modelling was used to generate evidence for the use of diagnostic strategies in the control and prevention, clinical management, and elimination of various infectious diseases— COVID-19, bacterial sepsis, HIV, and schistosomiasis (SCH). This evidence has and can be used to understand potential diagnostic impact, and to inform health policy by guiding the selection of the appropriate diagnostic strategies, their necessary technical specifications, and the conditions for their use. The diagnostics modelled included commercially available diagnostics, diagnostics still under development, or otherwise hypothetical diagnostics. The modelling evidence revealed 1) COVID-19 rapid diagnostics are insufficient at border crossings to prevent the importation of COVID-19; 2) COVID-19 rapid diagnostics could be feasible and cost-effective for school-based testing among symptomatic teachers and students; 3) a point-of-care test will need to be highly sensitive to reliably rule-out bacterial sepsis in infants, preventing deaths and unnecessary hospitalizations while maintaining cost-neutrality; 4) a molecular diagnostic for bacterial bloodstream infections and AMR could reduce deaths and inappropriate therapy, but only when implemented under optimal conditions; 5) a new rapid diagnostic for SCH could better support new prevalence mapping strategies, improving elimination programs while costing less than standard microscopy; 6) maternal HIV testing and retesting are crucial components of vertical transmission elimination programs. While POCTs can aid in reducing the burden of infectious diseases in resource-limited settings, healthcare infrastructure also requires focus and investment.