Interactions between brucellosis and environmental factors: spatiotemporal epidemiology from Xinjiang, China

Brucella is a highly adaptive pathogen, capable of withstanding environmental stress, adapting to multiple hosts, and transmitting through animal-environment interactions.This study investigates the potential impact of environmental factors on the incidence of brucellosis, aiming to identify spatiotemporal patterns between transmission sources and the environment.

We performed a comprehensive spatiotemporal analysis of brucellosis incidence in Xinjiang (2015-2023) by integrating satellite-derived environmental data, including temperature, vapor pressure deficit (VPD), NDVI, precipitation, and grazing intensity. Our study examined seasonal and regional transmission patterns, assessed lagged cumulative effects of environmental exposures, and and employed ridge regression modeling to address multicollinearity and quantify the potential contributions of these factors to disease incidence.

Northern Xinjiang (Yili, Changji, Tacheng) and Southern Xinjiang (Kashgar, Aksu) are the main grazing areas for cattle and sheep, accounting for 57.61% of brucellosis cases. Seasonal peaks occur in the second and third quarters (May-August). (2) The potential impact of environmental factors on brucellosis (M ± SD) was as follows: rainfall (0.42 ± 0.91 months lag, 1.95 ± 1.02 months accumulation), temperature (2.47 ± 0.95, 1.51 ± 0.92 ), VDP (0.52 ± 0.96, 1.52 ± 0.86 ), and NDVI (1.04 ± 1.35, 1.15 ± 0.59 ). (3) The incidence of brucellosis showed significant spatial and seasonal heterogeneity (P < 0.05), which may be related to the different local environments. In particular, regions with extreme climate conditions, such as large diurnal temperature fluctuations, heavy rainfall, and risks of sandstorms.

Environmental factors exhibit short-term lag effects, cumulative effects, and periodicity. Moderate climate cycles in spring and winter enhance immunity, while extreme climate cycles in summer and autumn increase physiological stress, thereby elevating the risk of disease transmission.