Spatiotemporal epidemiological characteristics of human brucellosis in Henan Province, from 1956 to 2023

In Henan, human brucellosis is a re-emerging disease; however, its epidemiological and spatiotemporal clustering profiles remain unclear. In this study, we employed joint point regression analysis and spatiotemporal scan analysis to uncover the epidemiological features of human brucellosis in this region. A total of 71,423 cases were recorded from 1956 to 2023, and the number of average annual reported cases was 1,050, with an average annual incidence rate of 1.3/100,000. The re-emerging epidemic of human brucellosis spans from 2000 to 2023, with an average annual incidence rate of 2.2/100,000 and an average of 2,114 annual reported cases. The number of affected counties increased from 39 in 2004 to at least 155 in 2023, and the incidence rate increased from 0.1023/100,000 in 2000 to 5.212/100,000 in 2023. These data imply that the human brucellosis epidemic continues to worsen and exhibits significant geographic expansion. Joint point regression analysis revealed a significant increasing trend of incidence rate from 1988 to 2023 (average annual percentage change [APC] = 24.46, P < 0.05). The persistently elevated incidence rate may be closely associated with multiple socioeconomic factors, such as extensive livestock farming practices, frequent transfer of infected animals, and enhanced diagnostic sensitivity. However, further research is needed. Spatiotemporal scan analysis showed that the high-high and low-low clusters were concentrated in the western and eastern parts of Henan Province, respectively, highlighting the importance of controlling livestock movement from western to eastern Henan Province. Effective containment of human brucellosis requires prioritization of animal control measures, including tests, culling, and vaccination, as well as improvements in surveillance, restrictions of the movement of infected livestock, and public health education among high-risk populations.