Institutionalizing school-based malaria surveillance to strengthen subnational stratification and policy in Tanzania: lessons from a decade of national implementation (2014–2025)

Abstract Background Effective subnational malaria control requires timely and geographically granular data, yet periodic nationally representative household surveys are generally not designed to provide frequent council-level estimates. Since 2014, Tanzania has implemented the School Malaria Parasitological Survey (SMPS), generating repeated council-level malaria prevalence estimates among school-aged children (SAC; 5–16 years). We describe the institutionalization and evolution of SMPS from 2014 to 2025 and its contribution to malaria surveillance, stratification, and programme decision-making. Methods We conducted a descriptive implementation study of six SMPS rounds. We reviewed survey protocols, implementation records, national reports, cost summaries, policy documents, and published analyses. SMPS uses repeated cross-sectional surveys in public primary schools across mainland Tanzania, with multistage stratified sampling embedded in government health and education structures. We summarized survey coverage, methodological changes, operational costs, and policy use; no new individual-level or inferential analysis was undertaken. Results Six SMPS rounds were implemented between 2014/15 and 2025, expanding from 49,113 SAC in 537 schools to 68,619 SAC in 655 schools. Parasite prevalence declined from 21.6% in 2015 to 11.3% in 2023 and 7.5% in 2025. SMPS progressively incorporated household, nutritional, molecular, geospatial and under-five surveillance, reaching 13,345 households and 9,577 under-five children in 2025. Council-level findings have informed malaria stratification, planning, intervention targeting and IPTsc expansion. In 2023, approximately 65,500 SAC were surveyed at an operational cost of about US$15 per child. Conclusions SMPS has operated for more than a decade as a government-led national platform in mainland Tanzania. It complements routine and population-based surveillance with council-level malaria data among SAC and informs subnational planning. The experience identifies practical requirements for sustained school-based surveillance: government ownership, decentralized delivery, standard methods, integrated data systems, and stable financing.