Kristen Nordlund, a spokeswoman for the Centers for Disease Control and Prevention, said the plane was diverted to a remote part of the Atlanta airport and that all the passengers were screened. The sick passengers were separated, she said.
“C.D.C. is working with the state of Georgia and other federal partners to determine a plan for these passengers,” she said in a statement. “Passengers with no symptoms upon arrival were given health information advising them to stay home for 14 days after returning from travel, monitor their health and practice social distancing as they continued to their final destination.”
Several passengers acknowledged that they or someone in their party had high temperatures when the C.D.C. checked. But as long as their temperatures fell after repeated tries, they were allowed to go home.
Passengers said they booked flights to California, Arizona, Florida and elsewhere across the United States and Canada.
Ms. Nordlund did not respond to questions asking whether it made sense to allow people who had been instructed to self-isolate to travel on commercial aircraft, potentially exposing them to other passengers.
“We got off the plane and you had to mark off a form asking, ‘Do you have a fever? Do you have a cough?’ I put that I had a fever and I went through secondary screening, because I was feeling terrible,” said Kelly Edge, a passenger from Miami. “I watched three-quarters of the people from the ship, and they did not do that. They marked themselves safe, got their temperatures taken and that was it.”
“They are roaming free,” she continued.
Ms. Edge said she went to an urgent care clinic afterward.
A fever is considered a telltale marker for the coronavirus, which has killed more than 10,000 people globally. (However, the man who had been aboard the Costa Luminosa and died in the Cayman Islands never had a fever, hospital officials there said.)