JMIR Publications

ABSTRACT

Background:

Young children are susceptible to enterovirus (EV) infections, which cause significant morbidity in this age group. However, knowledge of the epidemiology of EVs and circulating virus strains is mostly based on viruses detected in children with severe diseases, leading to contact with the healthcare system, whereas the vast reservoir of EVs that circulate in the general population is less characterized.

Objective:

This study investigated the characteristics of virus strains and the epidemiology of EVs circulating among young children in Taiwan from 2011 to 2020.

Methods:

Children diagnosed with EV infections from 2011 to 2020 were identified from the “routine national health insurance data monitoring disease system,” “real-time outbreak and disease surveillance system,” “national laboratory surveillance system,” and “Statistics of Communicable Diseases and Surveillance Report,” a dataset (secondary data) of the Taiwan Centers for Disease and Control (TCDC). Four primary outcomes were identified: epidemic features, characteristics of sporadic and cluster cases of EV infections, and main cluster institutions.

Results:

From 2011 to 2020, between 10 and 7600 person-times visited the hospitals for EV infections on an outpatient basis daily. Based on 2011 to 2020 emergency department EV infection surveillance data, the permillage of EV visits throughout the year ranged from 0.07‰ and 25.45‰. After typing by immunofluorescence assays, the dominant type was coxsackie A virus (CVA; 68.9%, 8844 of 12,829), with most constituting types CVA10 (2972), CVA2 (1404), CVA6 (1308), CVA4 (1243), CVA16 (875), and CVA5 (680); coxsackie B virus CVB (819 strains); echovirus (508 strains); EV-A71 (1694 strains); and EV-D68 (10 strains). There were statistically significant differences (p < 0.001) in case numbers of EV infections among EV strains from 2011 to 2020. Cases in 2012 had 15.088 times the odds of being EV-A71, cases in 2014 had 2.103 times the odds of being CVA, cases in 2015 had 1.569 times the odds of being echovirus, and cases in 2018 had 2.274 times the odds of being CVB as cases in other years. From 2011 to 2020, in an epidemic analysis of EV clusters, 57 EV clusters were reported. Clusters that tested positive included 53 (93.0%, 53 of 57) CVA cases [the major causes were CVA6 (32) and CVA10 (8)]. Populous institutions had the highest proportion (7 of 10) of EV clusters.

Conclusions:

This study is the first report of sporadic and cluster cases of EV infections from surveillance data (TCDC, 2011–2020). This information will be useful for policymakers and clinical experts to direct prevention and control activities to EV infections that cause the most severe illness and greatest burden to the Taiwanese.