Analysis on exposure disposal and epidemiological characteristics of rabies in Huzhou, Zhejiang Province from 2015 to 2024

Objective To analyze the epidemiological characteristics and prevention and treatment status of rabies exposure in Huzhou, Zhejiang Province from 2015 to 2024, and to provide references for improving the rabies prevention and control strategies. Methods The aggregated data of exposed individuals reported by the dog bite clinics in each district and county of the city, as well as the case-specific information, were collected. Descriptive epidemiological analysis was conducted on the temporal and regional distribution of the exposed population and their exposure characteristics. The time trend of the exposure rate was analyzed using the Joinpoint regression model, the trend change of the composition ratio was tested using the chi-square trend test, and individual case analysis was performed for rabies cases. Results Over a period of ten years, a total of 510,653 cases of exposure were reported, with an average annual exposure rate of 1,619.89 per 100,000 people. The Joinpoint regression analysis showed that the exposure rate increased rapidly from 2015 to 2018, decreased significantly from 2018 to 2021, and then rose again from 2021 to 2024. The exposure rate showed a peak in the summer and autumn seasons, with the peak occurring in July and August, accounting for 21.83% in total. Winter was the low season, with 6.1%, 5.7%, and 6.3% in December, January, and February respectively. The exposure rate was the highest in Anji County (1,814.49 per 100,000 people), and the lowest in Nanxun District (1,443.15 per 100,000 people). The main cause of injury was dogs (65.67%), and the proportion of cat injuries increased year by year (P<0.001). The exposed areas were mainly the upper and lower limbs, accounting for 51.35% and 43.27% respectively. The proportions of exposure to the upper limbs, trunk, and head and face all showed an upward trend (P<0.001). The exposure grades were mainly grade II (66.05%) and grade III (31.55%), and the proportion of grade III exposure showed an upward trend (P<0.001). The rate of passive immunization with rabies vaccine for the population with grade III exposure was 21.38%, showing an upward trend (P<0.001). A total of 9 cases of rabies were reported, all of which were male. Farmers accounted for 66.67% of the cases. All cases did not receive standardized treatment and full immunization. Conclusion The rabies exposure rate in Huzhou is on the rise, with a peak in the summer and autumn seasons. Dog bites are the main cause, and the proportion of cat bites has continued to increase. The passive immunization rate for the population with grade III exposure is low. It is recommended to strengthen the standardized management of dog bite clinics, standardize the disposal procedures for dog and cat bites, improve the accessibility of passive immunization preparations, strengthen education in rural areas, and enhance multi-department collaboration to promote animal source immunization to reduce the risk of rabies occurrence.