The news comes on the same day that the hospital ship was designated to begin treating COVID-19 patients in New York City, a reversal from the earlier policy that it could only treat patients not infected with the coronavirus.
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"The crew member had no contact with patients," the statement said.
Because the crew member did not come into contact with patients, it is highly likely that the crew member was asyptomatic when the Comfort left its homeport of Norfolk, Virginia, on March 28.
Other crew members who had contact with the crew member have tested negative for the virus, said a Navy official. But the official added that out of an abundance caution they will remain in isolation for several days regardless of the test results.
On Monday, President Donald Trump approved the hospital ship's transition to treat coronavirus patients due in large part to the small number of non-coronavirus patients the ship has treated during its week in New York City while civilian hospitals were overwhelmed by COVID-19 patients.
"Taking on more patients as quickly as possible is critical to helping the city of New York during this pandemic crisis," said Vice Adm. Andrew Lewis, commander of the U.S. Second Fleet. "We listened to the feedback from area health professionals and the community and believe this is the best way we can help our fellow Americans."
The field hospital at the Javits Center will be the military's primary facility for COVID-19 patients, but beginning immediately, the Comfort will accept trauma, emergency and urgent care patients without regard to their coronavirus status.
To minimize the risk to the ship's crew, they will be kept apart from the medical staff aboard the Comfort to prevent any inadvertent exposure of the virus.
And in a further step to prevent exposure, some of the ship's medical personnel -- who will be in contact with COVID-19 patients -- will be moved to a local hotel. That will reduce the number of personnel staying in the ship's berthing areas and improve social distancing.