Study population
This study was conducted between March 3, 2018 and March 3, 2020, as no positive sample of any virus was detected from March 4 to June 3, 2020. Children aged 0–10 years old with ARTI who came to see pediatricians in our hospital had their nasopharyngeal swabs collected and sent for analysis (n=11813). Because the specimens were collected at the time of admission or outpatient service, we could fully exclude the origin of ARTI in hospital. Upon receiving the nasopharyngeal swabs, the laboratory technicians would process and test the samples immediately.