Epidemiological characteristics and spatial distribution of human brucellosis in Heilongjiang, 2016–2019

  Objective   To understand the epidemiological characteristics and spatial distribution of human brucellosis in Heilongjiang province in recent years, and provide scientific evidence for the development of human brucellosis prevention and control strategies.

  Methods   The incidence data of human brucellosis in Heilongjiang from 2016 to 2019 were collected. Excel 2016 was used for data process and descriptive epidemiological analysis. The thematic map of human brucellosis incidence was generated by software QGIS 3.8. Software GeoDa 1.16 was used for global and local spatial autocorrelation analyses.

  Results   A total of 18 096 cases of human brucellosis were reported in Heilongjiang from 2016 to 2019. The annual incidence showed a fluctuating downward trend. Human brucellosis occurred all the year round during this period, and the peak of incidence was during March–July, accounting for 56.76% (10 272/18 096) of the total cases. The male to female ratio of the cases was 2.87∶1. The cases mainly occurred in age group 20–69 years, accounting for 94.71% of the total cases (17 139/18 096). The cases were mainly reported in farmers, accounting for 83.84% (15 172/18 096) of the total cases. A total of 129 counties (cities and districts) reported human brucellosis cases, and the top five counties (cities and districts) in terms of cumulative reported cases were Durbert, Nenjiang, Longjiang, Gannan and Zhaodong, with the cases accounting for 21.46% (3 884/18 096) of the total cases. The results of global spatial autocorrelation analysis showed that the annual incidence of human brucellosis in Heilongjiang was spatially clustered. Local spatial autocorrelation analysis and hotspot analysis indicated that the high incidence areas of human brucellosis in Heilongjiang were mainly in the southwest and southeast of the province.

  Conclusion   The annual incidence of human brucellosis in Heilongjiang showed a fluctuating decline trend. Spring and summer were the seasons with high incidence of human brucellosis. The populations at high risk were those aged 20–60 years, males and farmers, and the areas with high incidence of human brucellosis were in the southwestern and southeastern of Heilongjiang province.