The duration of the SARS-Cov-2 virus isolation depends on the severity of the course of the disease, it can last from 10 to 20 days, says Vladimir Chulanov, a freelance specialist of the Ministry of Health on infectious diseases.
Expert referred on studies showing that with a mild to moderate course of COVID-19, the virus can be shed on an average of ten days. Accordingly, during this period, a person can be contagious and should be maximally isolated from others. Moreover, in the case of a severe course, this period may increase to 20 days.
Vladimir Chulanov added that the isolation of the virus does not mean that the person is “infectious.”
Formerly Deputy Director for Clinical and Analytical Work of the Central Research Institute of Epidemiology of Rospotrebnadzor Natalya Pshenichnaya reported that the patient is maximally contagious two days before the onset of symptoms, less often – two to three days, and also on the first day of the disease. Transmission of the virus to others after the fifth day is unlikely.
In October, the Centers for Disease Control and Prevention (CDC) expanded data on the risks of infection and recommendations for isolating people with confirmed COVID-19. According to American doctors, the concentration of coronavirus RNA in the upper respiratory tract is guaranteed to decrease after the onset of symptoms. This means that a person is most infectious before they show symptoms of the disease, not after.
Virus replication is significantly reduced by the tenth day from the onset of symptoms. In patients with severe COVID-19, the virus can multiply for up to 20 days, but in 95% of cases, this process stops after 15 days. In mild to moderate cases, CDC recommends self-isolation for at least 10 days after the onset of symptoms, in severe cases, 20 days.