Those who have no symptoms of coronavirus need to be afraid

According to new research 'Stealth transmission' fuels fast spread of coronavirus outbreak from Columbia University, two-thirds of COVID-19 cases can come from people who have shown no symptoms of the disease. To do this, they created a mathematical model into which they loaded data on the movement of people around the country, the incubation period of the disease and the frequency of infection in order to simulate the first days of infection in China.

They found that by the time the authorities closed Wuhan, approximately 6-7 cases of infection remained unreported - and they were responsible for the infection of a significant part of the region.

Study co-author and Columbia University professor Jeffrey Shaman builds on previous research Vital Surveillances: The Epidemiological Characteristics of an Outbreak of 2019 Novel Coronavirus Diseases (COVID-19) believes these cases have been overlooked due to the fact that many people experience the disease with no or almost no symptoms. This confirms once again that total testing is necessary even for those who consider themselves healthy.

After China banned travel and began mass testing citizens, they were able to record most of the infections. But according to Dr. Shaman, travel bans in other countries are less reliable and testing is less accessible. This suggests that the real number of cases is 5-10 times higher than the official one. In the worst case scenario, this could mean 1.5 million infected already now.

“We know this is just the tip of the iceberg. The only question is how deep this iceberg really is. We cannot give the exact number, but if you do not live in a place where the authorities are actively looking for the infected and testing everyone they can, then most cases will go unnoticed. "

Thus, mass testing is needed to stop transmission of the virus from those who themselves do not know they are sick. It also reinforces the need to keep your distance from other people - and, if possible, stay indoors. Note that at the time of publication of the material in Russia, testing conducts only Rospotrebnadzor.

New York City Department of Health published in the official Twitter warning: "All New Yorkers should act as if they have already been in contact with patients with coronavirus." And, given the new data, the same can be said for a resident of any city in the world.