Journal of Tropical Diseases and Parasitology ›› 2025, Vol. 23 ›› Issue (2): 70-74,80.doi: 10.20199/j.issn.1672-2302.2025.02.002

• SPECIAL TOPICS ON PREVENTION AND CONTROL OF HAND, FOOTAND MOUTH DISEASE • Previous Articles     Next Articles

Epidemiological characteristics and risk factors of reinfection cases of hand, foot and mouth disease in Yunnan Province, 2020-2024

LI Zeying(), LIN Yan, JIA Yuchen, HUANG Tian, ZHENG Erda, SHENG Xiulian, CHEN Lihua, HE Jibo()   

  1. Yunnan Center for Disease Control and Prevention, Kunming 650500, Yunnan Province, China
  • Received:2025-03-06 Online:2025-04-20 Published:2025-06-03
  • Contact: HE Jibo, E-mail: ynhejibo@163.com

Abstract:

Objective To characterize the epidemiological features of recurrent hand, foot and mouth disease (HFMD) cases in Yunnan Province and identify risk factors of reinfection for scientific evidence in prevention and control of HFMD reinfection. Methods The case data on HFMD reported in Yunnan Province between 2020 and 2024 were retrieved via the Chinese Disease Prevention and Control Information System. Epidemiological characteristics of the reinfection cases were analyzed using descriptive epidemiology. Kaplan-Meier plotter was used to estimate the cumulative risk of HFMD reinfection, and Cox proportional hazards regression models were applied to analyze the risk factors for reinfection. Results A total of 12 191 HFMD reinfection cases were reported in Yunnan Province from 2020 to 2024, with a reinfection rate of 5.69%. The incidence peaked in June-July and October-November. By subgroups, higher reinfection rates were observed in males (5.96%), children aged <3 years (8.00%), home-based children (7.49%), laboratory-confirmed cases (6.19%), cases infected with other enteroviruses (7.12%), and cases with severe initial infections (9.87%). The median interval between infections was 14 (9-23) months. Kaplan-Meier curves indicated a rapid increase in reinfection risk within 20 months after the initial infection. Cox regression analysis revealed that the reinfection risks were higher for males [HR=1.149, 95%CI:(1.108, 1.191)], children aged <3 years [HR = 1.665, 95%CI:(1.570, 1.766)], urban residents [HR=1.064, 95% CI:(1.027, 1.103)], home-based children and childcare attendees [HR=5.251, 95%CI:(4.410, 6.251); HR=4.326, 95%CI:(3.653, 5.123)], laboratory-confirmed cases [HR=1.276, 95%CI:(1.209, 1.346)], and cases with severe initial infections [HR=1.502, 95%CI:(1.050, 2.149)]. Conclusion HFMD reinfection in Yunnan Province peaks in summer and autumn. Higher reinfection risks are associated with males, urban residents, young children, and severe initial infections, for which targeted interventions for these high-risk groups before epidemic peaks are recommended to reduce HFMD reinfection rates.

Key words: Hand, foot and mouth disease, Reinfection cases, Epidemiological characteristics, Cox proportional hazards regression model, Yunnan Province

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