Abstract / Summary
Background: Climate variability may synchronize vector-borne diseases across distinct transmission systems. This study evaluates climatic coherence among malaria, cutaneous leishmaniasis, and Chagas disease in Colombia and projects changes in environmental suitability under future climate scenarios. Methods: National surveillance, climatic, environmental, and socioeconomic data from 1980 to 2025 were analyzed using generalized additive models, distributed lag nonlinear models, and wavelet coherence. Annual series were used for interannual analyses, whereas monthly epidemiological and climatic series were used to evaluate delayed associations. Ecological niche models for selected vector species were projected to 2035 under three Coupled Model Intercomparison Project Phase 6 (CMIP6) climate scenarios. Results: El Niño–Southern Oscillation (ENSO) was associated with temperature, precipitation, and relative humidity anomalies. Incorporating ENSO variability improved model performance for malaria and cutaneous leishmaniasis beyond models based only on local climatic predictors. Delayed climatic responses differed among diseases; the most robust association was observed for malaria, with a 1 °C increase in temperature anomaly associated with 28.3% higher incidence over 3–8 months (relative risk [RR] = 1.28; 95% confidence interval [ CI ]: 1.03–1.60). Malaria showed the strongest temporal coherence with ENSO, followed by cutaneous leishmaniasis, whereas Chagas disease showed weaker patterns. By 2035, high-suitability areas increased by 6.2–9.8% for malaria and 8.8–16.8% for cutaneous leishmaniasis but decreased by 14.7–24.9% for Chagas disease. Spatial overlap remained high (mean Schoener's D = 0.886 under each scenario), while projected multi-vector co-occurrence ranged from 36,185 to 52,142 km 2 across the three 2035 scenarios. Conclusion: ENSO was associated with macroecological synchronization across transmission systems, although climatic responses differed among diseases. Future projections indicate spatial reorganization rather than uniform expansion, supporting integrated, climate-informed surveillance in areas of overlapping environmental suitability.