The most common source of infection is pneumonia patients infected with novel coronavirus, including symptomatic patients or asymptomatic carriers, which can be transmitted through respiratory droplets or contact. 2. Objects touched by the patient and aerosols filled with virus may also be the source of infection. 3. Wild animals such as bats, snakes and civets can carry the novel coronavirus, and the population is usually infected with the novel coronavirus through close contact or consumption of wild animals.