Since December 2019, cases of novel coronavirus pneumonia (COVID-19) have been reported in various provinces, municipalities and autonomous regions in China and many countries around the world[1,2,3]。 The disease is more common with mild symptoms, but the mortality rate of elderly and frail patients is high[4]。 The diagnosis of COVID-19 mainly relies on nucleic acid testing of novel coronavirus (2019-nCoV, hereinafter referred to as novel coronavirus)[4]。 As an acute respiratory infectious disease, COVID-19 has been included in the Class B infectious disease stipulated in the Law of the People's Republic of China on the Prevention and Control of Infectious Diseases, and is managed as a Class A infectious disease[4]。 On 11 March 2020, the WHO determined that COVID-19 had constituted a global pandemic. At present, the COVID-19 epidemic situation in China has stabilized, but considering asymptomatic infection, recurrence after treatment, and overseas imports, the prevention and control task cannot be neglected[5,6]。