A Meta-Analysis of Influencing Factors for Reinfection of Hand, Foot and Mouth Disease in China, Based on Adjusted Effect Estimates

<b>Background:</b> Numerous studies have reported on the epidemiology of hand, foot and mouth disease (HFMD) reinfection and its potential influencing factors; however, findings regarding reinfection rates as well as determinants such as gender, age, residence, and pathogens remain inconsistent. Due to this heterogeneity in reported outcomes, a comprehensive systematic review and meta-analysis are warranted to consolidate existing evidence. <b>Methods:</b> Effect estimates were expressed as reinfection rates, odds ratio (OR)/hazard ratio (HR) and 95% confidence intervals (CI). When necessary, data were converted to ensure consistency across comparison groups. <b>Results:</b> A thorough search was carried out using the predetermined literature retrieval approach across the PubMed, Web of Science, and Embase databases. Finally, 9 articles met the inclusion criteria and were included in this study. The results indicated that the overall reinfection rate for HFMD was 4.1% (95% CI: 2.0-6.2%). Males compared to females (overall effect = 1.256, 95% CI: 1.176-1.341), younger compared to older children (overall effect = 2.972, 95% CI: 1.512-5.843), scattered children compared to students (overall effect: 4.017, 95% CI: 1.560-10.344), and enterovirus 71 (EV71) compared to non-EV71 enteroviruses (overall effect = 0.71, 95% CI: 0.59-0.86) were associated with the HFMD reinfection. <b>Conclusions:</b> The overall HFMD reinfection rate was 4.1% (95% CI: 2.0-6.2%). Male, younger age, kindergarten children, and infection with non-EV71 enteroviruses (compared to EV71), were identified as significant risk factors for recurrent HFMD. Targeted intervention strategies should be developed for these high-risk populations to effectively reduce the incidence of reinfection.