The coronavirus can stay for hours to days on surfaces like counter tops and doorknobs. Severe acute respiratory syndrome (SARS), also caused by a coronavirus, was first reported in November 2002 in the Guangdong province of southern China.
https://webcbdlegal.com/how-old-do-you-have-to-be-to-buy-cbd-in-dc supports the idea that presymptomatic transmission can occur for just a few days before symptoms kick in. On 1312 , the CDC released data about such cases in Singapore from late January to mid-March.