Cohen: Almost half of coronavirus cases spread by those with no symptoms

State health secretary Mandy Cohen said Monday that a new analysis of many studies shows as many as 49% of cases of the novel coronavirus are spread by people who are not showing symptoms.

Some of those people may be infect others and may go on to show symptoms a few days later. Others may never show symptoms at all.

Anyone who has the infection and is not wearing a mask can easily spread it to people around them, Cohen said. That's what makes her three Ws – wear a face covering, wait six feet apart and wash hands regularly with soap and water – so important.

"That’s what is so hard about COVID-19, and it is why the governor and I and others continue to say we need to wear face coverings, Cohen said, "because it is so often that people can have COVID-19 and not know it and can infect a lot of folks."

Cohen said state leaders are especially worried about mass gatherings, like speedway races or large conventions. One so-called superspreader at one of those events could spark an outbreak of the virus, and people in attendance from other places could take it home with them.

The fact that coronavirus can be spread by those who are symptom-free raises a question about safety screenings. As many businesses open back up, they are relying on temperature checks for employees and customers. But if someone is infected and not showing symptoms, they wouldn't have a fever, so the screening wouldn't catch them.