Influencing Factors of Human Brucellosis in Inner Mongolia, China, 2014– 2023: A Bayesian Spatio-Temporal Analysis

Background Brucellosis is a neglected zoonotic disease and remains a global public health priority for the World Health Organization. Despite its significant global health burden, the disease remains substantially underreported in many regions. This study aimed to elucidate the associations between human brucellosis and its environmental, livestock-related, and socioeconomic determinants in Inner Mongolia from 2014 to 2023, utilizing a robust Bayesian spatiotemporal framework. Methods Descriptive epidemiological methods were employed to characterize the overall epidemic trends of brucellosis in Inner Mongolia. Subsequently, time series decomposition was utilized to analyze the temporal dynamics and seasonal patterns of brucellosis incidence. To identify key drivers of the disease, Spearman correlation analysis was performed to screen potential predictors and mitigate multicollinearity among meteorological, socioeconomic, and livestock-related factors. Finally, a Bayesian spatiotemporal model was developed to quantify the specific associations between these factors and brucellosis risk across the region. Results The incidence of brucellosis exhibited an initial upward trend followed by a decline, demonstrating pronounced seasonality in Inner Mongolia. Among environmental factors, atmospheric pressure (Relative Risk [RR] = 1.22, 95% Confidence Interval [CI]: 1.18–1.27) and wind speed (RR = 1.21, 95% CI: 1.16–1.26) were identified as major risk factors, while the Normalized Difference Vegetation Index (NDVI) exerted a protective effect (RR = 0.89, 95% CI: 0.87–0.91). Livestock density, particularly of sheep and cattle, was a key zoonotic driver. Notably, an inverted U-shaped relationship was observed between GDP and disease risk, with the highest risk (RR = 1.65, 95% CI:1.26–2.17) identified at intermediate economic levels (40–100 million yuan). This suggests an economic development paradox, where initial economic growth intensifies livestock production, thereby escalating short-term disease risks. Conclusions Human brucellosis in Inner Mongolia exhibits significant seasonality and is driven by a complex interplay of environmental and socioeconomic factors. Prevention and control efforts should be targeted at intermediate-income regions and intensified during the spring and summer months. Furthermore, strengthening animal immunization, enhancing occupational protection, and addressing the economic development paradoxthrough sustainable livestock management are critical to reducing the regional disease burden.