Chikungunya clusters in the state of Bahia: influence of environmental and social factors.

BACKGROUND: Chikungunya is an emerging disease that significantly impacts global public health and is associated with various environmental and social factors. This study aimed to identify the spatial and spatiotemporal clusters of chikungunya in the state of Brazilian Bahia, as well as their relationships with environmental and socioeconomic variables. METHODS: High- and low-risk clusters were analyzed for 2014-2023 using SatScan. Associations among socioeconomic, climatic, and vegetation characteristics were established using geostatistical estimates. RESULTS: Many high-risk clusters were observed at high densities in the southern, north-central, and south-central mesoregions. The months with the highest risk were February and March. A decreasing chikungunya trend of -0.6% per year was identified in the Bahian territory when the spatial variation of the temporal trends was analyzed. High-risk municipalities within the spatial chikungunya clusters generally had higher minimum annual and summer temperatures, lower thermal amplitudes, higher monthly and average summer precipitation levels, and higher socioeconomic indicators. The lowest vegetation cover was observed in the Caatinga biome, and the highest in the Atlantic Forest. CONCLUSIONS: Bahia has many high-risk clusters for chikungunya, underscoring the need to strengthen preventive and control measures through coordinated epidemiological surveillance services across the state.