The aim and design of this study
This study aims to explore the interlinks among the circulating EVs that
demonstrate a long-term regular seasonality of prevalence. And whether
the interactions are interfered by outer interventions such as NPIs of
COVID-19. Therefore, seasonal ARIMA models were used to forecast the
incidence of HFMD in order to analyze the potential impact of COVID-19
interventions on mitigating EV transmission. Spearman’s rank correlation
was conducted for the major serotypes to figure out the potential VVIs.
Data collection
Nanchang,
a city located at 115°27’-116°35’ E longitude and 28°10’-29°11’ N
latitude (Figure 1). Nanchang had a population of 6.4 million as of
2022, accounting for 12.5% of the population of Jiangxi Province. Since
June 2009, clinical specimens must be collected from all severe HFMD
cases, and the first 5 mild cases reported per month in each county or
district are tested for enteroviruses using real time RT-PCR by the
local CDCs (1, 15).
During 2019-2022, a total of 2296 clinically diagnosed HFMD cases were
collected from 9 hospitals in Nanchang, including Jiangxi Provincial
Children’s Hospital and 8 county and district sentinel hospitals. A
total of 2296 clinical specimens (1737 pharyngeal/throat swabs, 381 anal
swabs and 178 stools) were collected.
The study was approved by the ethics committee of the Nanchang Center
for Disease Control and Prevention, and the procedures were performed
according to the approved guidelines (Approval No. NCCDC-20100701).
Prior informed consent was obtained from patients or their parents for
sample collection.