Of all the coronavirus’s qualities, perhaps the most surprising has been that seemingly healthy people can spread it to others. This trait has made the virus difficult to contain, and continues to challenge efforts to identify and isolate infected people.

The coronavirus pandemic’s toll on the nation’s economy became emphatically clearer Thursday as the government detailed the most devastating three-month collapse on record, which wiped away nearly five years of growth.

Gross domestic product, the broadest measure of goods and services produced, fell 9.5 percent in the second quarter of the year as consumers cut back spending, businesses pared investments and global trade dried up, the Commerce Department said.