Dynamic Modeling and Control of Brucellosis in a Metapopulation Network Considering Animal Transportation: A Case Study of Xinjiang, China.

Cross-regional animal transportation is a crucial factor in the spatial transmission of brucellosis, and infections occurring during transportation cannot be overlooked. Clarifying the spatiotemporal transmission patterns of brucellosis under animal transportation mechanisms is of great significance for enabling targeted prevention and control of the disease. Based on data from the Xinjiang Animal Husbandry and Veterinary Big Data Platform, we constructed a directed and weighted sheep transportation network. We established a coupled human-sheep metapopulation model for brucellosis that incorporates infection during animal transportation, thereby providing a more accurate description of brucellosis spread across the metapopulation network. The epidemic threshold was derived theoretically. For the application, a brucellosis transmission model was simulated based on the constructed sheep transportation network in Xinjiang. It was observed that with an increase in transportation rate, epidemic threshold first decreases then increases, indicating that excessively high or low transportation rates should be avoided. Notably, epidemic threshold also increases as the infection rate during transportation rises, which exacerbates brucellosis epidemics in practice, so its potential risks cannot be ignored. For brucellosis control, we first identified key regions and key transportation routes using network centrality, then simulated the control effect with practical control measures. The results demonstrated that strengthening quarantine at checkpoints and reducing sheep transportation between key areas and other regions are more effective than implementing the same measures on critical transportation routes. Specifically, node degree centrality can effectively identify key regions. In early control stage, prioritize reducing internal infection rates through regular quarantine, purification and standardized breeding management; in the middle and late stages, the most effective control is increase culling rate. Our study clarifies the impact of animal transportation and infections occurring during transportation, and analyzes the effectiveness of different control measures from network structure perspective, providing a theoretical basis for brucellosis control in Xinjiang and other regions.