Novel coronavirus pneumonia is a respiratory transmitted disease, and it is now believed that its most important mode of transmission is droplet transmission, especially close droplet transmission, and the farthest distance of droplet transmission may not exceed 2 m. If two people are facing each other and the distance is within 1 m, the risk of virus transmission is high and it is called close contact transmission. In addition to droplet transmission, there is also aerosol transmission, i.e. the amount of virus in the patient is large and the virus may float in the air for some time. The process is similar to smoking, and even though the specific individual smoking is not seen, the odor may float in the air for a few minutes and the smell of smoke may still be detected. In rooms with less space, such as elevators, trains, and airplane bathrooms, where air circulation is poor, the virus may remain in the air for several minutes after the patient coughs. When others enter the small space, they may still be infected due to aerosol inhalation even though they have not directly touched the patient. In addition, some studies have found that nucleic acid can also be found in the urine and feces of patients, which does not exclude the possibility of being a transmission route, but whether it has transmission significance is subject to further investigation and research. Content source: Dr. You Lai