Factors related to the mortality risk of severe hand, foot, and mouth diseases (HFMD)：a 5-year hospital-based survey in Guangxi, Southern China

Abstract

Abstract Background: To understand the factors influencing clinical outcomes of severe hand, foot, and mouth diseases (HFMD), and to provide scientific evidence for reducing the mortality risk of severe HFMD.Methods: From 2014 to 2018, children diagnosed with severe HFMD cases in Guangxi, China, were enrolled in this hospital-based study. The epidemiological data obtained through face-to-face interviews with the parents and guardians. Univariate and multivariate logistics regression models were used to analyze the factors influencing the clinical outcomes of severe HFMD. Survival analysis was performed by the Kaplan-Meier method. The impact of the EV-A71 vaccination on inpatient mortality was analyzed by a comparison approach. Stratified analysis and propensity score matching (PSM) analysis were performed to eliminate the influence of potential confounding factors.Results: A total of 1,565 severe HFMD cases were enrolled in this survey, including 1474 (94.19%) survival cases and 91 (5.81%) death cases. The multivariate logistic analysis demonstrated that males, HFMD history of playmates in the last three months, first visit to the village hospital, time from the first visit to admission less than two days, critical illness, and having no rash symptoms were the independent risk factors for severe HFMD cases (all P<0.05). While EV-A71 vaccination was a protective factor (P<0.05). Stratified analysis and Kaplan-Meier survival analysis further confirmed the result of the multivariate regression. The 1:1 PSM of the EV-A71 vaccination group versus the non-vaccination group showed 2.34% of death in the vaccination group and 7.01% of death in the non- vaccination group. The EV-A71 vaccination protected 66.62% of the death of severe HFMD cases, with an effective index of 3.00.Conclusions: The mortality risk of severe HFMD in Guangxi was related to gender, hospital grade, clinical severity at admission, EV-A71 vaccination, and rash symptom. EV-A71 vaccination can significantly reduce mortality among severe HFMD. The findings are of great significance for the effective prevention and control of HFMD in Guangxi, southern China.