Epidemiological characteristics of human brucellosis in Hainan province, 2009−2022

Objective To analyze the epidemiological characteristics of human brucellosis in Hainan province, 2009–2022, and to provide evidence for further discussion and formulation of brucellosis prevention and control measures.

Methods The epidemiological data of human brucellosis in Hainan province from 2009 to 2022 were collected and analyzed by descriptive epidemiology, serological monitoring data were collected at each monitoring site. χ² test was used to analyze the incidence rates in different years and different genders.

Results A total of 140 cases of brucellosis were reported in Hainan province from 2009 to 2022, with an average annual incidence of 0.11/100 000, which showed an increasing trend year by year (χ²=164.602, P<0.001). The incidence peak was from March to September. Cases of brucellosis were reported in 17 cities and counties (89.47% of the total). Dongfang, Changjiang, Baisha, Ledong and Lingao were the five neighboring cities and counties with the highest incidence. The number of cities and counties with the disease increased year by year. Among the 140 confirmed cases, 97 were males (annual reporting rate 0.13/100 000) and 43 were females (annual reporting rate 0.07/100 000), the difference was statistically significant (χ²=21.174, P<0.001). The majority of cases were 30–69 years old, accounting for 77.85% of all cases. The occupation distribution is mainly farmers, accounting for 53.57%. A total of 13175 key occupational population were tested serologically, 161 were found positive (positive rate 1.22%). Breeding cattle, sheep, pigs and other domestic animals, meat processing and slaughtering and other direct contact with infected animals and pollutants were the main causes of infection, accounting for 95.00%. Food-borne infection accounted for 2.86%. 77.14% of the cases were seen within 30 days of onset.

Conclusion The incidence of human brucellosis in Hainan province is increasing year by year, and has rapidly spread to many cities and counties. It is suggested that relevant departments strengthen joint prevention and control, and take appropriate control measures according to the epidemiological characteristics.