CNBC:

“The number of actual cases in the country is likely significantly higher, state and local officials say. Testing in the U.S. has been hampered by delays and a restrictive diagnostic criteria that limited who could get tested.

“On March 1, there were roughly 100 confirmed cases of the rapidly spreading virus in the U.S., according to the Centers for Disease Control and Prevention. By March 10, 1,039 cases had been confirmed, according to Hopkins.”

And it is not just the old who are vulnerable. NYT:

Younger Adults Make Up Big Portion of Coronavirus Hospitalizations in U.S.