Abstract:
Objective To analysis the spatiotemporal clustering characteristics of human brucellosis in Yunnan province from 2006 to 2024, and provide references for the development of targeted prevention and control strategies.
Methods The incidence data and the area, time, and population distributions of human brucellosis cases in Yunnan from 2006 to 2024 were collected from National Notifiable Infectious Disease Reporting Information System. Additionally, the serological surveillance data of human brucellosis in Yunnan from 2010 to 2024 were also collected. Descriptive epidemiological methods and software ArcGIS 10.8 were used to analyze the epidemiological characteristics and spatiotemporal clustering patterns of human brucellosis.
Results From 2006 to 2024, Yunnan province reported a cumulative total of 7360 human brucellosis cases. The annual case count exhibited a marked escalation, rising from a single confirmed case in 2006 to 2124 cases in 2024. Concurrently, the number of affected counties/districts expanded from 1 to 101 during the same period. Serological surveillance data revealed a fluctuating yet significant upward trend in seropositivity rates, increasing from 0.94% (2010) to 4.60% (2023). These findings demonstrate both a sustained intensification of the epidemic and progressive geographic dissemination across the province. The number of reported cases varied significantly by month (χ2=66.030, P<0.05), sex (χ2=1116.031, P<0.05), age group (χ2=5742.262, P<0.05), and occupation (χ2=75515.430, P<0.05). The highest number of cases was reported in July, with the epidemic predominantly occurring in summer and autumn. The peak incidence occurred later than in northern regions, possibly due to local climate conditions and livestock farming practices. male-to-female ratio was 2.28∶1. Most cases were farmers, with the highest proportion aged 30–70 years, showing a gradual aging trend, which may be associated with older individuals' greater involvement in animal husbandry and weaker disease prevention awareness. Global spatial autocorrelation analysis revealed significant positive spatial autocorrelation in human brucellosis prevalence from 2009 to 2024, indicating overall spatiotemporal clustering (P<0.05). Local spatial autocorrelation analysis showed that the number of “high-high” clustering areas increased from 2 counties (districts) in 2009 to 11 in 2024, primarily concentrated in central and southeastern Yunnan.
Conclusion The brucellosis epidemic in Yunnan Province continues to worsen, exhibiting distinct occupational and seasonal characteristics. Middle-aged and elderly male farmers constitute the key population for targeted prevention and control, while central and southeastern Yunnan represent the priority regions for intervention efforts.