Introduction
Brucellosis is a globally important zoonotic disease affecting humans and a range of livestock. In China, human brucellosis has re-emerged over the past two decades, spreading from northern regions toward central and southern areas. This article synthesizes spatiotemporal epidemiological evidence for Henan Province from 1956 to 2023, highlighting historical shifts, regional clustering, and implications for control strategies.
Data and Methods Summary
Data were drawn from the National Notifiable Infectious Disease Reporting Information System, covering 1956–2023. Analyses included trend assessment, joinpoint regression to identify significant changes in incidence, retrospective space-time scanning to detect clusters, and geographic visualization using ArcGIS. The study examined incidence rates, county- and city-level distribution, and temporal transitions to illuminate how brucellosis evolved in this central province.
Overall Epidemiology (1956–2023)
Across 1956–2023, Henan recorded 71,423 human brucellosis cases, with an average national-like burden of 1.3/100,000 per year. Two major epidemic phases emerged: an early era (1956–1980) with a peak in 1969, followed by a low-epidemic period (1981–1999). A re-emergence occurred from 2000 onward as livestock industries expanded, culminating in rising incidence through 2023. The first peak reached 11.79/100,000 in 1969; a later peak appeared around 2015 before a further rise to 5.21/100,000 in 2023. The pattern mirrors broader national trends of north-to-south diffusion within China.
Spatial Spread and Geographic Burden
From 2004 to 2023, Henan reported 50,404 brucellosis cases across 18 cities, with Pingdingshan and Nanyang bearing the heaviest caseloads. The province showed a pronounced northwest-to-southeast expansion, with 130 counties reporting no cases in 2004 but 155 counties affected by 2023. Average annual cases rose markedly, and city-level annual growth rates varied widely (3.25% to 43.23%), reflecting heterogeneous transmission dynamics across the province.
County- and City-Level Trends
Joinpoint analysis revealed multiple regional shifts. Zhengzhou and Sanmenxia exhibited three joinpoints, while others showed two or one, indicating different inflection points in local transmission. Overall, all regions experienced statistically significant upward trends (P < 0.001), with inter-county growth rates ranging from moderate to very rapid. This heterogeneity underscores the role of local farming practices, animal movement, and veterinary controls in shaping human risk.
Spatiotemporal Clustering
Retrospective space-time scanning identified two key clusters during 2004–2023. A high-high cluster (RR = 5.37) spanning 31 counties in the west, particularly around Nanyang, Luoyang, Pingdingshan, Sanmenxia, and Zhumadian, persisted from 2014 to 2023. A contrasting low-low cluster (RR = 0.24) remained in eastern Henan from 2010 to 2019, signaling regional disparities and potential protective factors in that area. The analysis indicates a western concentration with a trend toward eastern expansion, highlighting the need for targeted interventions in high-risk districts while not neglecting emerging eastern foci.
Implications for Public Health and Control
The Henan experience reflects the broader North China pattern of brucellosis expansion linked to intensified animal husbandry and animal movement. Control measures should emphasize:
– Strengthening veterinary vaccination programs in high-risk areas, particularly in western Henan and neighboring provinces.
– Regulating animal movement and improving traceability to curb cross-regional spread.
– Enhancing surveillance systems and diagnostic concordance to reduce underreporting and misclassification.
– Coordinated One Health approaches integrating animal health, food safety, and human health sectors to mitigate transmission from livestock to people.
Limitations and Future Directions
Study limitations include potential underreporting inherent to NNDRS data and evolving diagnostic criteria over time. Future work should integrate molecular typing of Brucella strains, longitudinal field surveys in high-risk counties, and prospective surveillance with standardized case definitions to refine transmission models and inform more precise control policies.
Conclusion
From 1956 to 2023, Henan Province experienced a long-standing brucellosis burden that transitioned from historic endemicity to a re-emerging, geographically expanding public health challenge. The combination of regional clusters and rising incidence signals a critical window for intensified, targeted interventions to stem the spread and protect both human and animal health.
