Molecular epidemiology and clinical features of hand, foot and mouth disease requiring hospitalization after the use of enterovirus A71 inactivated vaccine in chengdu, China, 2017-2022: a descriptive study

• Published in: Emerging microbes & infections Vol. 11; no. 1; pp. 2510 - 2519
• Main Authors: Duan, Xiaoxia, Zhang, Chaoyong, Wang, Xiao, Ren, Xueling, Peng, Hongxia, Tang, Xueqin, Zhang, Liangzhi, Chen, Zhenhua, Ye, Yan, Zheng, Mengmou, Zhong, Wanzhen, Chen, Xiyue, Zeng, Yilan, Yuan, Ping, Long, Lu
• Format: Journal Article
• Language: English
• Published: London Taylor & Francis 31.12.2022; Taylor & Francis Ltd; Taylor & Francis Group
• Subjects: clinical features; enterovirus; Epidemiology; EV-A71 vaccine; Hand foot and mouth disease; molecular epidemiology; Public health; Vaccines; China
• ISSN: 2222-1751; 2222-1751
• DOI: 10.1080/22221751.2022.2125346

Three inactivated enterovirus A71 (EV-A71) vaccines have been widely vaccinated among children in the targeted age group in mainland China since mid-2016. However, comprehensive virological surveillance of hand, foot and mouth disease (HFMD) over multiple years after the use of EV-A71 vaccines has rarely been conducted. Using long-term data extracted from the Public Health and Clinical Center of Chengdu, we described the clinical, aetiological, and epidemiological characteristics of HFMD inpatients after the use of EV-A71 vaccines from 2017 through 2022. A total of 5115 patients were selected for analysis with a male-to-female ratio of 1.63:1 and were mostly under 5 years of age (97.6%). Among these cases, 4.3% presented with severe symptoms, and 4.1% of severe cases experienced significant complications. EV-A71 was no longer the major serotype for laboratory-confirmed HFMD, responsible for 15.6% of severe cases and 1.2% of mild cases. A significant downwards trend of EV-A71 infections was observed after the use of EV-A71 vaccines (P for trend < 0.001). Coxsackievirus A6 was the predominant pathogen, accounting for 63.5% of mild cases and 36.2% of severe cases. Coxsackievirus A10 (CV-A10) and A16 were sporadically detected, and an upwards trend was observed in the proportion of CV-A10 infections. This study provides baseline molecular epidemiology for the evaluation of EV-A71 vaccination impact and potential serotype replacement based on HFMD inpatients. Additional nationwide and population-based epidemiologic and serologic studies are essential to elucidate HFMD dynamics after the use of EV-A71 vaccines, and to inform public health authorities to introduce optimized intervention strategies.