Residual Malaria Burden and Strategic Targeting of Intermittent Preventive Treatment for Schoolchildren in Oyo State, Nigeria: An Integrated Geospatial Decision-Support Framework

Abstract

School-aged children (5–15 years) represent an increasingly important but underprotected reservoir of malaria transmission in Nigeria, yet evidence for geographically prioritized intermittent preventive treatment for schoolchildren (IPTsc) remains limited. This study developed an integrated geospatial decision-support framework to quantify the residual malaria burden, identify persistent transmission reservoirs, and evaluate the operational feasibility of school-based IPTsc implementation in Oyo State, Nigeria. Multisource datasets comprising routine underfive malaria surveillance, Malaria Atlas Project (MAP) transmission products (2000–2024), WorldPop population data, GRID3 primary schools, health facilities, road networks, travel-time accessibility, and nighttime lights were harmonized within a geographic information system. Three complementary analytical components were developed: (i) a residual burden uncertainty index (RBUI) integrating underfive malaria burdens with persistent transmission; (ii) a transmission reservoir uncertainty index (TRUI) combining current transmission intensity with long-term persistence; and (iii) a school-level school-level opportunity index (SOI) and IPTsc priority index incorporating the school-age population, healthcare accessibility, and operational feasibility. The analysis revealed pronounced spatial heterogeneity in the residual malaria burden and transmission persistence across the state. The school-level assessment included 2,839 primary schools serving an estimated 2.66 million children aged 5–15 years during 2025, 40.0% of which were classified as high- or very high-priority for IPTsc implementation. The operational assessment indicated that 93.5% of the schools were suitable for health worker-supported delivery, whereas only 6.5% required teacher-supported administration following appropriate training because of reduced healthcare accessibility. The proposed framework integrates epidemiological risk with implementation readiness, providing a reproducible and scalable approach for evidence-based IPTsc prioritization. By linking malaria burden, transmission persistence, school infrastructure, and delivery logistics, the framework offers practical decision support for geographically targeted malaria prevention and can be readily adapted to other malaria-endemic settings.