Novel coronavirus pneumonia can also occur in people who have not been exposed to Wuhan, and this is more common in diagnosed cases, mainly because of the presence of latently infected people. A latently infected person who tests positive for the virus, but has no symptoms of his own, will not even realize he is a carrier until he is tested for the virus, and so the virus can spread before he is isolated. For example, the first case of novel coronavirus pneumonia in Japan, a driver who went to the airport to pick up expatriates returning to Japan from Wuhan, did not wear a mask and contracted the virus after coming into contact with these people. However, he was asymptomatic and frequently contacted passengers, spreading the virus to others. The virus is now actively resuming work in all areas, but some areas are experiencing small outbreaks after the resumption of work. This kind of outbreak is caused by hidden infected people with the virus, who have been to the infected area or have contact with people in the infected area, but do not have such a feeling themselves, and have not been tested for the virus, so when they are tracked down, it is found to be a hidden infected person, which results in a small-scale outbreak. So people who have not been in contact with Wuhan can also get the new coronavirus pneumonia. Source: Dr. Yurai