It is generally recognized that infection with a novel coronavirus is contagious until it is cured, including the incubation period. Generally speaking, the new coronavirus is most contagious when obvious respiratory symptoms appear on the 3rd to 7th day after the onset of the disease, but this varies from person to person. New coronary infected patients generally have a clear history of contact before the onset of the disease, mainly through the respiratory tract, close contact transmission, has the characteristics of strong transmission, etc., the onset of the disease often have fever, malaise, cough and other symptoms, usually about 3 ~ 7 days after the onset of the disease, when there are obvious respiratory symptoms, the most contagious. At present, the main prevalent strain is Omicron, and the infection is dominated by mild and asymptomatic infected patients, most of whom show fever, dry cough and fatigue. Some patients have loss of smell and taste as the first symptom, while some have no obvious clinical symptoms. Symptomatic treatment and disease monitoring are required during isolation management, and prompt medical attention is recommended in case of exacerbation.