Novel coronavirus infection can be detected in people with asymptomatic viral infections. If it is early in the onset, the infection can be followed by no clinical manifestations, such as fever and pneumonia. As the epidemic progresses, asymptomatic infected individuals are identified. As a source of infection, roughly a few percent of patients may be asymptomatic carriers of the virus. Patients test positive for nucleic acid on nasopharyngeal swabs. As long as the virus is multiplying in the respiratory tract, it can be detected by laboratory tests even if there are no symptoms. It has been found that the nucleic acid values of some asymptomatic infected patients are not lower than those of symptomatic patients, suggesting the significance of transmission in asymptomatic infected patients, who have a similar ability to transmit the virus as symptomatic people. Content source: Dr. Arigato