An asymptomatic patient with novel coronavirus infection is defined as an asymptomatic patient when the patient has no obvious clinical manifestations of novel coronavirus infection, i.e., no dry cough, fever, fatigue, chest tightness, shortness of breath, dyspnea, or obvious clinical symptoms such as nasal congestion, runny nose, sore throat, muscle aches, or diarrhea. An asymptomatic patient may be in the incubation period or may have a mild infection with no obvious clinical manifestations, but it is still infectious. Therefore, patients with an epidemiologic history, i.e., who have recently traveled to an infected area, come into contact with patients who may be infected, or have a cluster of cases, should be observed in isolation early, usually for 2 weeks. If patients present with clinical manifestations, early tests should be performed to detect the presence of novel coronavirus infection.