This is the first time that U.S. sailors have tested positive aboard a Navy ship while at sea.
The three sailors have been flown to an undisclosed U.S. medical facility in the Pacific region, said Thomas Modly, the acting Secretary of the Navy at a Pentagon briefing. Sailors among the rest of the ship's crew of 5,000, who came into contact with the three sailors, have been protectively quarantined.
"We've identified all those folks that they've had contact with and we're quarantining them as well," Modly said. "This is an example of our ability to keep our ships deployed at sea."
Overall, the Navy has 86 personnel who have tested positive for COVID-19, including 57 sailors. The rest are civilians, dependents or contractors.
It was unclear if the sailors became infected with the coronavirus following the ship's most recent port of call in early March to Da Nang, Vietnam
"It would be difficult to tie down these active cases to that particular port visit," said Adm. Mike Gilday, the chief of naval operations. "We've had aircraft flying to and from the ship and so we just don't want to say that it was that particular port visit."
Gilday said that prior to the port call, Navy officials carefully considered whether to proceed with the visit. He noted that at the time of the scheduled port of call there were only 16 cases of COVID-19 -- all of them in northern Vietnam, far from the port located in central Vietnam.
Careful screening of returning sailors was carried out before they boarded the carrier, which then followed the Navy's new guidance to maintain 14 days at sea following a port of call.
The three sailors tested positive 15 days after the port of call.
This past weekend the Navy sent medical teams to three large ships in the Pacific -- including the carrier Roosevelt -- that could carry out "batch" testing of units aboard the ships instead of individual tests. But it appears that the three sailors exhibited symptoms, including fever and body aches, and received individual tests that were flown to shore for final analysis.