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

## TL;DR

This study finds that 4.1% of children in China get hand, foot and mouth disease again, with boys, younger kids, and those infected with non-EV71 viruses being more likely to experience reinfection.

## Contribution

The study provides a meta-analysis consolidating evidence on HFMD reinfection risk factors in China.

## Key findings

- The overall HFMD reinfection rate was 4.1% (95% CI: 2.0–6.2%).
- Males had a higher reinfection risk compared to females (OR = 1.256).
- Younger children and those infected with non-EV71 viruses were more likely to be reinfected.

## Abstract

Background: 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. Methods: 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. Results: 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. Conclusions: 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.