Geospatial Point-of-Care Testing Strategies for COVID-19 Resilience in Resource-Poor Settings: Rural Cambodia Field Study (Preprint)

Abstract

BACKGROUND Point-of-care testing (POCT) generates intrinsically fast, inherently spatial, and immediately actionable results. Lessons learned in rural Cambodia and America create a framework for planning and mobilizing POCT with telehealth intervention. Timely diagnosis can help communities assess the spread of highly infectious diseases, mitigate outbreaks, and manage risk in rural and resource-limited settings. OBJECTIVE To identify needs for POCT in Cambodian border provinces during peak COVID-19 outbreaks and to quantify geospatial gaps in access to diagnostics during community lockdowns. METHODS Focus groups, interactive learners, webinar participants, virtual contacts, academic experts, public health experts, and local officials defined needs and priorities for diagnostics in rural Cambodia during the height of the COVID-19 pandemic. We analyzed geographic distances and transit times to testing in border provinces and assessed a high-risk province (Banteay Meanchey) where people crossed borders daily and spread disease. We strategized access to rapid antigen testing and proposed sites for molecular diagnostics. RESULTS Cambodia struggled with outbreaks which were difficult to manage in rural and isolated areas where diagnostics were insufficient to meet needs. Border province (N=17) median transit time to testing sites was 73 (range 1-494) minutes and in high-risk Banteay Meanchey Province (N=9 districts), 90 (10-150) minutes. Within Cambodian border provinces, maximum versus minimum distances and access times for testing differed significantly (P<0.05). Pareto plots revealed geospatial gaps in access to testing for people not centrally located. At the time of epidemic peaks in Southeast Asia, mathematical analyses showed only one rapid antigen test available met World Health Organization sensitivity >80% requirement. We observed that in rural Yolo and Solano Counties, California, vending machines and public libraries dispensing free COVID-19 test kits 24/7 improved public access to diagnostics. Mobile testing vans equipped with COVID-19 antigen, RT-PCR, and multiplex influenza A/B testing proved useful for differential diagnosis, public awareness, travel certifications, and integrated telehealth treatment. CONCLUSIONS Rural diagnostic portals implemented in America demonstrate a feasible public health strategy for limited-resource countries. Automated dispensers and mobile POCT can respond on demand to COVID-19 surges and enhance public health preparedness for future outbreaks. Point-of-need planning can help build resilience and assure spatial justice. Public health assets should include higher quality, lower cost, readily accessible, and user friendly POC technologies, such as self-testing for diagnosis, distributed border detection for surveillance, and mobile diagnostics vans for quick telehealth treatment of symptomatic infected patients. High-risk settings will benefit from synthesis of geospatially optimized POCT, automated 24/7 test access, and timely diagnosis of symptomatic patients at points of need now, during new surges, and in future pandemics.