WASHINGTON: Back in late February, when the United States thought it had sealed itself off from the coronavirus, a Chicago resident with mild respiratory symptoms went to pay his respects at a funeral as a friend of the family.
Three days later, he attended a birthday party with his relatives. Advertisement Advertisement The man, who was unaware he had the COVID-19 illness, set off a chain of transmissions that infected 15 other people, three of whom died, the Centers of Disease Control and