Abstract:
Objective To analyze the epidemiological characteristics and spatiotemporal clustering patterns of hand, foot and mouth disease (HFMD) in Leshan, Sichuan province, from 2009 to 2024, and provide evidence for the improvement of HFMD prevention strategies.
Methods Descriptive epidemiological analysis, global/local spatial autocorrelation, and spatiotemporal scan statistics were employed to systematically analyze the epidemiological characteristics and spatial distribution patterns of HFMD in Leshan.
Results From 2009 to 2024, a total of 40 498 HFMD cases were reported in Leshan, with the average annual incidence of 78.13/100 000. In the cases, 140 were severe cases, including 4 deaths. The cases were mainly home-cared 1–<4 years old children, the incidence was significantly higher in males than in females (1.41∶1). Between 2009 and 2019, the incidence of HFMD showed a bimodal seasonal pattern with peaks occurring during April-June and October-December, whereas after 2020 it showed a single annual peak. Shizhongqu district had the highest incidence rate (136.27/100 000), whereas Yi autonomous counties showed markedly lower rates(χ2=2 698.334,P < 0.01). Virological surveillance demonstrated a progressive decline in the detection rate of enterovirus A71 (EV-A71), while coxsackievirus A16 (CVA16) exhibited a biennial circulation pattern. Other enteroviruses maintained persistent circulation throughout the study period. Spatiotemporal analysis indicated no significant global clustering of HFMD cases in Leshan. However, local spatial autocorrelation identified distinct clustering patterns (low-low, high-high, and low-high). Spatiotemporal scanning detected 1 primary and 1-2 secondary clusters annually. The primary clustering areas shifted from Emeishan, Shizhongqu, and Wutongqiao during 2009-2016 to Shawan, Jiajiang, and Muchuan from 2017 to 2024. The annual clustering periods were consistently around June and November.
Conclusion The incidence of HFMD showed distinct seasonality and local spatiotemporal clustering in Leshan from 2009 to 2024. It is necessary to pay attention to home-cared 1–<4 years old children, conduct precise prevention and control, strengthen case management in the core districts (e.g., Shizhong district), intercept imported cases in the diffusion zones (e.g., Jiajiang county), and intensify surveillance and health education in Mabian Yi autonomous county and Ebian Yi autonomous county.