Abstract:

Objective To analyze the epidemiological characteristics and trend changes of brucellosis in Tangshan City of Hebei Province from 2007 to 2023，and provide reference for brucellosis prevention and control work. Methods The incidence data and basic population data of brucellosis in Tangshan City from 2007 to 2023 in the Chinese Disease Prevention and Control Information System were collected. Descriptive epidemiology were used to analyze the epidemiological characteristics，and Joinpoint regression models were used to analyze the trend of brucellosis over time and by age. Results From 2007 to 2023，a total of 4 191 cases of brucellosis were reported in Tangshan City，with a incidence rate of 3.22/100 000. The incidence of brucellosis in Tangshan City was on the rise，with the average annual percent change（AAPC） of 17.33%（t=5.685，P<0.01）. There was no statistically significant difference in the incidence trend between males and females（t=0.626，P>0.05），with a gender ratio of 2.95 ∶ 1，which was higher than the national level（2.49 ∶ 1）. The onset of the disease was concentrated between April to June with a distinct seasonality. The age of onset was concentrated in the age group of 51-<71 years old，with the high-incidence age group shifted from younger to older age groups gradually. The top three occupations in terms of composition ratio were farmers（86.50%），workers（3.03%），and home workers and unemployed individuals（2.31%），with an upward trend in the composition ratio of home workers and unemployed individuals（AAPC=30.15%，t=2.429，P<0.05）. The top three areas in terms of incidence were Qian'an City（8.24/100 000），Laoting County（6.14/100 000） and Luannan County（4.67/100 000）. There was an overall increasing trend in incidence in most counties from 2007 to 2023（AAPC>0，P<0.05）. Conclusion From 2007 to 2023，although the incidence rate of brucellosis in Tangshan City was slightly lower than the national level，it shows an overall upward trend，with characteristics such as a high incidence from April to June，middle-aged and elderly male farmers aged 51-<70 being high-risk groups，and clustering in areas with developed animal husbandry. Based on these characteristics，it is necessary to strengthen multi-departmental collaboration，precise intervention and scientific and technological support，and establish a long-term prevention and control mechanism to curb the development of the epidemic.

Key words: Brucellosis, Epidemiological characteristics, Joinpoint regression model, Annual percent change, Disease prevention and control