Study on the Epidemiological Characteristics of Common Enterovirus among
Pediatric Patients in Hangzhou, China: A Comparison between the
Pre-COVID-19, COVID-19 Pandemic, and Post-COVID-19 Periods
Abstract
Nonpharmaceutical interventions (NPIs) against coronavirus disease 2019
(COVID-19) reduced the prevalence of coronavirus among children and
influenced the transmission of other viruses. This study investigates
the impact of NPIs on human enterovirus (HEV) among children in
Hangzhou, China. We collected and analyzed the laboratory results and
clinical data of children diagnosed with hand, foot, and mouth disease
(HFMD) or herpangina (HA) during the following periods: pre-COVID-19
(January 2019 to December 2019), COVID-19 pandemic (January 2020 to
December 2022), and post-COVID-19 (January to August 2023). A total of
38,582 specimens that met the inclusion criteria were enrolled, of which
1,777 (5.58%) tested positive for enterovirus. In comparison to the
pre-COVID-19 period, which had 695 (5.63%) HEV-positive specimens, the
numbers dramatically decreased to 69 (1.19%), 398 (5.12%), and 112
(1.58%) in 2020, 2021, and 2022, respectively, but significantly
increased to 503 (9.00%) in 2023. Seasonal peaks of infections occurred
between May and August each year, with positive rates of 10.58%,
25.27%, 31.74%, and 10.97%, respectively. Notably, June and July
accounted for half of all cases, with a rate of 57.01%. The difference
in the positive rates of HEV infection between males and females was
statistically significant (P<0.005), with 5.12%
(1,084/21,176) and 4.43% (693/15,629) testing positive, respectively,
resulting in a male to female ratio of 1.56:1. Among the same age
groups, children aged 3-5 years and 5-7 years had the highest positive
rates at 11.03% (342/3,102) and 10.03% (205/2,024), respectively,
after synthesizing five years of data. The detection rate of
HEV-positive cases increased with age, but after the age of 7, the rate
declined. The detected types of HEV indicated that enterovirus 71
(EV-A71) and coxsackievirus A16 (CV-A16) are no longer the two common
pathogens causing HFMD and HA. In conclusion, NPIs for COVID-19 are
highly effective in reducing the transmission of HEV. However, the
relaxation of NPIs results in a resurgence of HEVs, surpassing
prepandemic levels. Active awareness and surveillance of the
epidemiological characteristics of HEV are essential for preventing,
controlling, and managing the development of HFMD and HA, as well as
contributing to the development of a multivalent HFMD vaccine.