Human brucellosis (HB) is one of the most widespread zoonoses globally. In mainland China, it remains a persistent challenge. This study aimed to elucidate the spatiotemporal dynamics of HB and identify its associated environmental factors from 2004 to 2022. Joinpoint regression was applied to assess temporal trends in HB incidence at national and provincial levels. Spatial autocorrelation analyses were conducted to detect spatial clusters and identify high-risk regions. Bayesian spatiotemporal models were used to examine the associations between environmental factors and HB incidence. From 2004 to 2022, the incidence of HB ranged from 0.88 to 4.95 cases per 100,000, with six northern provinces (Inner Mongolia, Shanxi, Heilongjiang, Xinjiang, Hebei, and Liaoning) consistently ranking among the top 10 nationwide. National joinpoint analysis indicated a significant overall increase (AAPC = 8.56%, 95% CI: 7.12–10.81, P < 0.001). Provincially, AAPCs were positive in all provinces except Tibet, with a significantly higher mean AAPC in southern provinces than in northern ones (33.33% vs. 16.83%; P = 0.012). In terms of spatial clustering, High-High clusters were concentrated in the north (e.g., Inner Mongolia, Heilongjiang, Jilin, Liaoning, Gansu), whereas Low-Low clusters persisted in the south (e.g., Guizhou, Hunan, Jiangxi, Zhejiang, Guangxi). HB incidence was positively associated with relative humidity, sheep inventory, milk production, and railway passenger turnover, and was negatively associated with average temperature, NDVI, and effective irrigation area. Given the spatial heterogeneity and the increasing burden of brucellosis across mainland China, targeted strategies are required to curb the persistently high incidence in the north and the rapidly rising incidence in the south. To this end, the environmental factors identified in this study provide importance evidence to guide targeted interventions.
Ju et al. (Sat,) studied this question.