In Washington, where it was still Sunday afternoon, a fierce debate broke out: The State Department and a top Trump administration health official wanted to forge ahead. The infected passengers had no symptoms and could be segregated on the plane in a plastic-lined enclosure. But officials at the Centers for Disease Control and Prevention disagreed, contending they could still spread the virus. The CDC believed the 14 should not be flown back with uninfected passengers.

“It was like the worst nightmare,” said a senior U.S. official involved in the decision, speaking on the condition of anonymity to describe private conversations. “Quite frankly, the alternative could have been pulling grandma out in the pouring rain, and that would have been bad, too.”

The State Department won the argument. But unhappy CDC officials demanded to be left out of the news release that explained that infected people were being flown back to the United States — a move that would nearly double the number of known coronavirus cases in this country.