Spatial characteristics and driving factors of human brucellosis and plague infections in the Meriones unguiculatus plague focus in China

The <i>Meriones unguiculatus</i> plague focus in China constitutes a key zoonotic-disease hotspot where brucellosis and plague co-circulate, posing a syndemic public-health challenge. An integrated spatial risk assessment framework was constructed to systematically contrast the spatial patterns and drivers of the two pathogens and to pinpoint potential interfaces for integrated surveillance. During 2022-2025, 17,289 blood samples were collected from 13,703 individuals. The overall seroprevalence was 19.50% for brucellosis and 0.47% for plague. Spatial analysis revealed pronounced spatial clustering of brucellosis (global Moran's <i>I</i> = 0.295, <i>P</i> < 0.05), while plague seropositivity was sporadic or locally clustered; areas of dual high-risk for both diseases were specifically identified. By integrating serological results with multi-dimensional data, a spatially enhanced random forest model (MSE = 0.005, RMSE = 0.068; AUC = 0.878) was constructed for risk assessment. Significant predictors for brucellosis included male gender, livestock-related occupation, higher vegetation index (NDVI), elevated PM₁₀ levels, sheep density, and proximity to dairy retail outlets. NDVI and livestock operation density emerged as key indicators for joint surveillance. These findings suggest that the interplay between agricultural intensification and climate variability appears to jointly facilitate transmission, underscoring the importance of adopting integrated surveillance strategies to control these zoonotic diseases.