Around 15 sailors who came into contact with the first presumed positive individual were also taken off the ship and quarantined around the same time, Rieger said.

The other sailor who tested positive for coronavirus was out of the state and had not been on board the ship when they fell ill. That person has since recovered.

Vice Joint Chiefs Chairman Gen. Hyten said during a press briefing on Thursday that there have been "a very small number of breakouts" of symptomatic individuals on board the Nimitz, but “it's not a big spike at this point." Rieger confirmed that there are no active cases on the ship, and no one on board is awaiting test results.

The crew has stayed aboard the ship pierside since April 1, and no one except those exhibiting symptoms have been allowed off the ship in an attempt to reduce sailors’ exposure and more easily monitor them for symptoms. The sailors are not getting their temperatures checked daily, but have been instructed to self-isolate and call the medical team — who have the proper personal protective equipment — for a more thorough screening if they start to feel symptoms associated with Covid-19.

Non-crew members who need to board the ship for whatever reason, such as a contractor called upon to fix a piece of equipment, will first be screened pierside where a medical tent has been set up, Rieger said.

The USS Theodore Roosevelt is battling the spread of the virus on board, with more than 400 positive Covid-19 cases so far. The ship, which was on a Pacific deployment, is now docked in Guam and has been testing sailors and quarantining them in hotel rooms on the island.

Two other carriers — the USS Ronald Reagan undergoing maintenance in Japan, and the USS Carl Vinson, which is finishing maintenance in Puget Sound — have also reported a small number of positive cases.