Abstract
BACKGROUND: Due to the absence of cross-protection among various enterovirus subtypes, reinfection with hand, foot, and mouth disease (HFMD) is frequently observed. This study aimed to investigate the epidemiological characteristics and influential factors of HFMD reinfection in Chongqing, southwest China. METHODS: The data for cases of HFMD in Chongqing from 2009 to 2022 were obtained from the China Information System for Disease Control and Prevention. Cases of HFMD reinfection were identified through uniform definition. Descriptive epidemiology was employed to depict characteristics of HFMD reinfection cases. Binary logistic regression analysis was used to explore the factors influencing HFMD reinfection. RESULTS: Among the 591,297 HFMD patients, 19,678 cases (3.33%) were classified as reinfections. The reinfection rates for males and females were 3.74% and 3.26%, respectively, and the difference was statistically significant (χ(2) = 90.490, P < 0.001). Among different age groups, children aged under 12 months had the highest HFMD reinfection rate of 6.07%, and the reinfection rate decreased with increased age (Z = 66.83, P (trend) < 0.001). In terms of occupation, scattered children had significantly higher HFMD reinfection rates compared to children in kindergarten, school students, and adults (χ(2) = 2,814.322, P < 0.001). The reinfection rate was higher for other enteroviruses compared to enterovirus A71 (EV-A71) and Coxsackievirus A16 (CVA16) (χ(2) = 74.851, P < 0.001). The reinfection rate was significantly higher in urban areas (3.82%) than that in rural areas (2.85%). The binary logistic regression analysis indicated that male, younger age, living in urban areas, and infection with other enteroviruses were risk factors for HFMD reinfection. CONCLUSION: This study investigated the burden of HFMD reinfection in Chongqing. Male, younger age, residing in urban areas, and infection with other enteroviruses as the serotype of HFMD were associated with a higher likelihood of reinfection. It is necessary to develop targeted health education programs and intervention measures to reduce the reinfection of HFMD in susceptible individuals.