Military medical investigators are probing what officials say is the second confirmed coronavirus test tied to the crew of the amphibious warship Boxer, part of a proliferation of COVID-19 cases across the country.

Navy commands on Wednesday reported that a sailor at Helicopter Maritime Strike Squadron 48 in Florida tested positive for the respiratory disease, as did a civilian worker at the Naval Construction Battalion Center’s Naval Exchange in Gulfport, Mississippi.

The San Diego sailor’s results came back on Wednesday, four days after another enlisted sailor from Boxer tested positive for COVID-19.

“There is no indication that the sailors were in close contact with each other, but a thorough contact investigation continues,” U.S. Pacific Fleet spokesman Cmdr. Myers J. Vasquez told Navy Times.

Boxer remains at Naval Base San Diego and is not at sea. Both sailors have been confined to their residences off base. Anyone who came into close contact with them also has been isolated and is self-monitoring for COVID-19 symptoms.

Officials told Navy Times that the latest positive case tied to the warship isn’t believed to be linked to a coronavirus cluster that blossomed inside the Training Support Center at Naval Base San Diego.

That outbreak snared the first case from Boxer’s crew. He’s believed to have contracted COVID-19 from an instructor.

A third enlisted sailor from Naval Base Point Loma who also was attending a course at the schoolhouse at Naval Base San Diego caught coronavirus, forcing Naval Education and Training Command to shutter a large number of classrooms there.

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But authorities told Navy Times that there’s no evidence the two sailors from Boxer had close contact with each other.

One was a blue shirt and the other a member of the Goat Locker. Although the chief briefly visited Boxer on March 16, he’s not believed to have had close contact with any crew members and both sailors worked in different divisions.

One of the patients recently took leave locally and the other returned from out of town.

Navy shutters Naval Base San Diego schoolhouse amid coronavirus cluster The link between two of the cases appears to be the training center on Naval Base San Diego.

Sailors standing watch continue to stay overnight on the warship, but their sleeping arrangements are now spaced at least 6 feet away from each other, per Pentagon and Centers for Disease Control and Prevention guidelines.

“Sailors are reporting to the ship to maintain readiness,” said spokesman Vasquez. "In the U.S. Pacific Fleet and across the Navy, our three missions are to protect sailors and their families, prevent the spread of the virus, and ensure warfighting readiness.

“We are taking every measure possible to protect the health of our force."

Officials insist that Boxer’s crew has developed what they’re calling “an aggressive mitigation strategy” to halt the spread of the disease, including establishing a medical station at the quarterdeck to screen all personnel coming aboard the vessel.

Quarterdeck watchstanders wear nitrile gloves to prevent touching others, and they’ve been ordered to maintain social distancing similar to the sleeping arrangements. Group gatherings and formations are minimized and sailors are “deep cleaning” the ship with bleach twice daily, according to a prepared statement emailed from the Pentagon to Navy Times.

Antiseptic wipes and hand sanitizer are located in workspaces near computers, mess decks, common areas and the tool issue, officials added.

The ship’s gyms are closed and there are no self-serve meals on the mess decks, chief petty officer mess or wardroom.

An MH-60R Sea Hawk helicopter assigned to the Vipers of Helicopter Maritime Strike Squadron 48 takes off from the guided-missile destroyer Roosevelt on May 18 in the Atlantic Ocean. (Mass Communication Specialist 2nd Class Austin Ingram/Navy)

Three days after taking the test for coronavirus, a sailor assigned to Helicopter Maritime Strike Squadron 48 at Naval Station Mayport in Florida was confirmed positive for the disease.

Like other Navy COVID-19 patients, the sailor remains confined to an off-base residence while health authorities conduct a contact investigation to trace any others possibly exposed to the virus.

“The health of our people and the readiness of our force is critical. Our people are our most valuable assets,” said Naval Air Force Atlantic spokeswoman Cmdr. Jennifer Cragg.

Cragg declined to provide details about that investigation, but officials are not sure other Vipers were exposed to the disease. The sailor had been traveling on orders and did not report back to the unit after showing symptoms for the virus.

The patient is believed to be the first sailor in an East Coast naval aviation squadron to contract the disease.

And in Mississippi, a NEX employee is undergoing evaluation and treatment while public health agencies investigate potential contacts with other people, according to a Pentagon press release.

“In consultation with the State of Mississippi Public Health and Navy public health officials it was deemed that a quarantine for additional personnel was not needed due to the lack of exposure to other NEX employees/associates or patrons,” the prepared statement indicated.