Abstract:

ObjectiveTo analyze the epidemiological characteristics of brucellosis in China and the surveillance results from the sentinel sites, in order to provide a basis for formulating precise prevention and control strategies for this infection. Methods Data on brucellosis cases and public health emergencies from 2021 to 2025 were retrieved from the Chinese Disease Prevention and Control Information System. Additionally, serological screening data of brucellosis in key populations and epidemic monitoring data of livestock were collected. The epidemiological characteristics and monitoring results of brucellosis across the country were described and analyzed. Results A total of 324 725 cases of brucellosis were reported from 2021 to 2025. The number of cases and incidence rate in 2023 were the highest (70 439 cases, 5.00/100 000). Brucellosis was mainly reported from March to August (214 062 cases, accounting for 65.92%). The cases were mainly concentrated in Inner Mongolia (83 503 cases), Xinjiang (34 770 cases), and Gansu (25 359 cases), accounting for 44.23% of the total reported cases. The affected population was dominated by male (229 378 cases, 70.64%), and majority of the cases were involved in population aged 50-59 years (104 429 cases, 32.16%). The occupation was mainly associated with farmers and herders (273 211 cases, 84.14%). A total of 328 brucellosis-related public health emergencies were reported, which involved 963 cases, with most events reported in Shandong Province (123 events). From 2021 to 2025, a total of 303 218 key populations were monitored at national-level surveillance sites, among whom 13 180 were tested seropositive, with a positive rate of 4.35%. In total, 13 273 730 sheep were quarantined, which identified 15 645 seropositive cases (positive rate: 0.12%). Similarly, 2 448 935 cattle underwent quarantine, among which 9 680 were seropositive (positive rate: 0.40%). A total of 20 441 samples were cultured for etiological surveillance of acute?phase patients, from which 1 419 strains were isolated, the predominant species was sheep strain type 3 (343 strains, 24.17%). Conclusion The national brucellosis epidemic remains severe, characterized by north-south divergence as well as occupational and seasonal clustering. It is necessary to deepen cross-sectoral joint prevention and control, implement differentiated prevention and control strategies for the north and south regions, carry out seasonal precise control, and strengthen livestock-related surveillance and laboratory testing capacity building.

Key words: Brucellosis, Epidemiological characteristics, Surveillance