[Epidemiological characteristics and spatio-temporal clustering analysis of anthrax in China from 2014 to 2024]

Objective: To analyze the distribution and epidemiological characteristics of anthrax in China from 2014 to 2024 to provide a scientific basis for identifying key prevention and control areas, detecting new epidemic areas, and formulating targeted prevention and control strategies. Methods: Spatial autocorrelation analysis and epidemiological analysis of anthrax data in China from 2014 to 2024 were applied with ArcGIS 10.8 and RStudio 4.2 software. Results: A total of 3 722 anthrax cases were reported in China from 2014 to 2024, with an overall fluctuating upward trend, including 25 fatal cases, with a case-fatality rate of 0.67%. Anthrosis cases primarily occurred between July and September, totaling 1 855 cases, which accounted for 49.84% of all reported cases. Among the cases, 2 731 were male and 991 were female, with a male-to-female ratio of 2.76∶1, showing a statistically significant difference in incidence (χ²=34.89, P<0.001). The majority of cases were concentrated in the 30-49 age group, with a cumulative total of 2 632 cases, representing 70.71% of all cases. In terms of occupational distribution, herders and farmers were the most affected groups, accounting for 51.40% and 37.99% of total cases, respectively. From 2014 to 2024, the top three provinces with the highest cumulative reported cases were Gansu (821 cases), Qinghai (784 cases), and Sichuan (640 cases). Newly reported cases have shown a trend of spreading to North China, northern Heilongjiang Province, and southwestern Xizang Autonomous Region. Spatial autocorrelation analysis indicated clustering in anthrax distribution from 2014 to 2024 (the Moran's I values ranged from 0.271 1 to 0.395 8, P<0.001). Highly clustered areas were mainly located in Qinghai Province and the Xizang Autonomous Region, with a scattered distribution in northwestern Inner Mongolia. A total of 73 clustering events were recorded, involving 421 cases, with an attack rate of 0.89%, accounting for 11.31% of all cases. These clustering events exhibited periodic fluctuations. Conclusions: From 2014 to 2024, human anthrax cases in China showed an overall increasing trend, primarily concentrated in Gansu Province, Qinghai Province and Sichuan Province. The epidemic season was predominantly summer and autumn, with the most affected demographic being males aged 30-49 years. Strengthening prevention and control guidance in these regions and among high-risk populations is essential to reduce the occurrence and spread of anthrax.