A negative screening is good news, but at present one screening is not enough for a diagnosis. Only people who have traveled to an infected area or been exposed to an infected patient are screened. The incubation period of the virus varies, and although the average time is 3-7 days, some patients have an incubation period of up to 1-2 weeks or even longer. Although cases are rare, they still need to be taken seriously. A single negative nucleic acid test does not completely confirm the absence of infection, and continued observation is needed, along with attention to the presence of associated symptoms. If the virus is a true infection, there may be other reactions such as fever, dry cough, fatigue, and difficulty in breathing. If there are symptoms, it is important to get another nucleic acid test, as a negative test does not confirm the absence of infection. Source: Dr. Yurai