Optimizing the location of point-of-care infant HIV testing devices in Zimbabwe to maximize impact and value: A modeling analysis

BACKGROUND: Early HIV diagnosis in infants is essential for timely antiretroviral therapy (ART) initiation, but requires virologic testing - often performed in centralized laboratories, which can delay results and treatment initiation. Point-of-care (POC) testing delivers same-day results, facilitating prompt diagnosis and treatment, but availability is limited in low-resource settings. We aimed to optimally locate POC machines to improve life expectancy (LE) and net health benefit (NHB) for infants born to people with HIV in Zimbabwe. METHODS: We linked the validated CEPAC-Pediatric HIV microsimulation model, populated with detailed subnational programmatic data, with a location-optimization model for 122 clinics in Matabeleland South's 7 districts. Simulating two testing strategies - conventional laboratory-based and POC machine-based - we projected: 30-day result-return, 30-day ART initiation for children with HIV (CWH), LE, HIV-related healthcare costs, and NHB. We maximized LE or NHB for infants tested at 6-10 weeks old. FINDINGS: With 17 POC devices in current locations, a projected 43.8% of tested infants would receive HIV test results, with 41.6% of CWH starting ART within 30 days. Undiscounted LE would be 67.85 years (25.91 among CWH), with average discounted lifetime costs of $202/infant. Optimizing locations to maximize LE would retain 6 devices in current locations and move 11 to new sites, leading to projected 52.6% 30-day result-return, 50.0% 30-day ART initiation, and 67.88 years LE (27.04 among CWH), costing $211/infant. Maximizing NHB with a willingness-to-pay threshold ≥ $1,164 (66% of Zimbabwe's GDP per capita) would render the same optimal locations as maximizing LE. Additional optimally-located machines would further improve LE. Ensuring one machine per district while maximizing LE would require one additional machine and would increase 30-day result-return (to 53.3%), ART initiation (to 50.6%), and LE (to 67.88 years, 27.11 for CWH), costing $212/infant. INTERPRETATION: Data-driven optimization of POC machine location could improve HIV detection and increase life expectancy and net health benefit for infants undergoing HIV testing in Zimbabwe.