COVID-19 can be spread before it causes symptoms, when it produces symptoms like those of the common cold, and as many as 12 days after recovery, according to a virologic analysis of nine infected patients published today on the preprint server medRxiv.
In SARS, it took 7 to 10 days after onset until peak RNA concentrations (of up to 5x105 copies per swab) were reached. In the present study, peak concentrations were reached before day 5, and were more than 1,000 times higher.
The findings confirm that COVID-19 is spread simply through breathing, even without coughing, he said. They also challenge the idea that contact with contaminated surfaces is a primary means of spread, Osterholm said.
http://www.cidrap.umn.edu/news-perspective/2020/03/study-highlights-eas…