Epidemiological characteristics of brucellosis in Shaanxi, 2019 – 2020

  Objective  To understand the epidemiological characteristics and incidence trend of brucellosis in Shaanxi province from 2019 to 2020 and provide evidence for the targeted brucellosis prevention and control.

  Methods  The incidence data of brucellosis cases and outbreaks in Shaanxi from 2019 to 2020 were collected for a descriptive epidemiological analysis to understand the population, area and time distributions of brucellosis cases in Shaanxi by using software SPSS 25.0 and ArcGIS 10.8. At the same time, the characteristics of outbreaks and risk of different infection routes were also analyzed.

  Results  A total of 2 254 brucellosis cases were reported in Shaanxi from 2019 to 2020, with an annual incidence rate of 2.92/100 000. The cases were mainly reported from April to September, which were mainly distributed in Guanzhong and northern Shaanxi, and there was statistically significant difference in the annual incidence rate among Guanzhong, northern Shaanxi and southern Shaanxi ( χ²=1338.771, P<0.001). Most patients were men, the difference in annual incidence rate between men and women had statistical significance (χ²=440.140, P<0.001), and most cases (71.25%) were aged 40–69 years. Farmers were mostly affected. A total of 27 outbreaks were reported during 2019–2020, involving 218 serum positive cases, including 175 cases and 43 latent infections. The small-scale outbreaks with 3–5 cases accounted for 51.85%. The places where the outbreaks occurred were mainly family farms (48.15%), the infection route of direct contact with skin and mucous membranes accounted for 44.44%. The differences in infection rate through direct contact with skin and mucous membrane, respiratory tract and digestive tract were significant (P<0.001). The relative risk of brucellosis risk through direct contact with skin and mucous membrane, respiratory tract and digestive tract were 21.257 (95% CI: 13.621–33.183), 15.408 (95% CI: 8.927–26.600) and 15.895 (95% CI: 10.117–24.957) respectively. A total of 10 273 livestock were detected, in which 349 were killed in 27 outbreaks. A total of 69 Brucella strains were isolated and identified, which were mainly Br melitensis type 3.

  Conclusion  It is necessary to adhere and improve the joint prevention and control mechanism, strengthen the quarantine of sick animal and improve people′s knowledge, attitude and practice of brucellosis prevention and control to prevent and control brucellosis in Shaanxi.