Asymptomatic persons with novel coronavirus pneumonia can also transmit the virus, and the source of infection is clearly defined in the fifth edition of the diagnostic and treatment guidelines, and the source of infection currently includes patients seen with novel coronavirus infections, which are symptomatic patients who have most likely been quarantined, and asymptomatic infected persons who can be the source of infection, and asymptomatic infected persons are now also determined to be the source of infection, so each person can be an infected person or a Victims. Because there are many infected people, such as imported pneumonia, who may not have any symptoms, or may have contacted patients or suspected patients during the long incubation period, but may not know it, so it is not possible to tell who or where the asymptomatic infected people are, so everyone should do a good job of prevention and control, less partying, sitting at home for self-isolation, opening windows more often to ventilate the house, disinfecting, and so on. Content source: Dr. Yurai