From environmental exposure to disease burden: Institutional capacity, structural vulnerability, and global malaria inequality, 2000-2023.

Malaria burden varies markedly between countries with similar environmental conditions. We examined national associations between malaria incidence, institutional capacity, economic development, structural vulnerability and selected environmental indicators during 2000-2023. An ecological panel comprised 4,382 complete country-years across 186 countries. Year-fixed-effects models related log(incidence + 1) to standardised predictors, with country-clustered uncertainty. Vulnerability was positively associated with incidence (β = 0.931, p = .007), whereas GDP per capita was inversely associated (β = -2.014, p < .001). Institutional capacity and the selected environmental indicators were not statistically significant after adjustment. With country-and-year fixed effects, vulnerability attenuated to β = 0.406 (p = .232), while GDP remained inversely associated. Excluding the malaria-related ND-GAIN indicator retained the positive year-effects association; excluding the whole health sector and changing sector coverage affected the findings. GDP showed a relatively consistent association; vulnerability depended on specification and composite construction. National aggregation, incomplete source provenance and potential confounding limit interpretation. These ecological associations do not establish causal pathways. Subnational environmental, intervention and health-system data are needed to investigate the proposed mechanisms.