Epidemiological characteristics and analysis of hand-foot-mouth disease epidemics with EV71 vaccination in Henan Province, China
Authors: Song Chunlan , Zhang Xue , Li Peng , Yuan Ke , Cui Junhao , Wang Yangji , Fu Shuqin , Li Wanying , Dai Lizhong 
Published: June 2022

Abstract
Background: Hand-foot-month disease (HFMD) is an infectious disease occurring primarily in children caused by enteroviruses. HFMD has occurred in various areas in recent years. Many research works on HFMD in different regions have been discussed and published in relevant journals. However, in some large cities, such as Zhengzhou, the epidemiological characteristics and spatiotemporal patterns of individual-level HFMD cases are unclear. The purpose of this work is to investigate the epidemiological characteristics and explore the surveillance data of HFMD in Henan province, to provide appropriate public health measures and strategies for the prevention and treatment of HFMD. Meanwhile, we hope that this work can provide prospective guidance for the analysis of epidemic and etiological study on HFMD following EV71 vaccination in Henan Province.Methods: All patients with hand-foot-mouth disease admitted to Zhengzhou Children's Hospital in Zhengzhou City, Henan Province were selected using convenient sampling method. Detailed information including the age, occupation, pathogen, location, and gender were recorded to analyze the epidemiological characteristics of HFMD epidemics. Data from individual-level HFMD cases were examined using Local Indicators of Spatial Association (LISA) analysis to identify spatial autocorrelation of HFMD incidence. The results are described in ArcMap10.5.Results: Before vaccination, a total of 19,512 cases of hand-foot-mouth disease were reported in Zhengzhou Children's Hospital (61% male, 39% female), including 237 severe cases and 2 deaths in 2016. After EV-A71vaccination, the result showed that the number of HMFD patients has decreased. The number of patients with HMFD infection caused by the EV 71 virus has dropped dramatically. HMFD caused by EV 71 virus can be completely controlled within 2 years after vaccination. Results showed that the incidence of HFMD cases showed obvious seasonal distribution, with the highest monthly incidence occurring in 4-7. Most of the pediatric patients were distributed in the <5 age group. Nearly 98.4% of cases were scattered or kindergarten children. The areas with relatively high relative risk are mainly located in Jinshui, Huiji, Guancheng districts of Zhengzhou (the proportion of the population at risk is about 49%), where the incidence of HFMD has a high-high positive spatial autocorrelation. The most likely space-time cluster is located in the north-central area of Jinshui district in Zhengzhou.Conclusions: EV71 vaccination can effectively prevent and control the number of HMFD patients in Henan province. The main patients with HFMD in Henan Province are preschool children in the <5 age group, and boys are more likely to suffer from HFMD. The peak monthly incidence is mainly concentrated in 4-7. Cities with large population flow like Zhengzhou and Xuchang are the high-incidence cities of HFMD. In particular, northern cities such as Jinshui district and Zhengdong district are the districts with the highest incidence of HFMD.