Global co-hotspots of dengue, malaria, and yellow fever: a comparative spatiotemporal analysis across 142 countries

Abstract Dengue, malaria, and yellow fever remain major mosquito-borne public health threats in tropical and subtropical regions. Yet most global spatial studies have focused on single diseases or on potential transmission suitability rather than empirically observed shared burden. We therefore sought to identify robust global co-hotspots of these three diseases across 142 countries from 1990 to 2023, treating mosquito-borne diseases as an integrated public health problem. Using annual country-level incidence data from the Global Burden of Disease study and demographic, health-system, and climate covariates, we compared a fully Bayesian shared-component model, a neural network model with spatial-lag features, and a two-stage hybrid model. Shared scores were standardised for cross-model comparison and externally validated against an independent mortality anchor. Overall, 29 countries were classified as consensus hotspots, all in sub-Saharan Africa, while seven countries formed a moderate-agreement watch list at the margins of the main hotspot belt, suggesting potential transition zones of shared burden. By shifting the analytical focus from potential suitability to the empirical identification of realised burden and shared control vulnerability, this study provides actionable global evidence on where mosquito-borne disease prevention and control may be most structurally constrained. The findings may support more integrated prioritisation of vector control, surveillance, and health-system preparedness across countries.