A total of seven crew members aboard the USNS Mercy hospital ship have tested positive for COVID-19, Navy officials confirmed this week.

A Navy spokesman said the crew members, who were part of the ship’s medical treatment facility, are currently isolated off the ship and just over 100 crew members who were in contact with them remain in quarantine. So far, they have tested negative for the coronavirus except for one crew member who was the fifth confirmed positive case. The coronavirus’ incubation period can be up to two weeks, according to health officials.

“The ship is following protocols and taking every precaution to ensure the health and safety of all crew members and patients on board,” said Lt. Joseph Pfaff in an email. “This will not affect the ability for Mercy to receive patients at this time.”

There are currently 18 patients on board with Mercy personnel having treated 48 patients overall. There are no COVID-19 positive patients.

Pfaff said patients are first identified by local health officials and then screened for the virus before being transferred to the ship. The patient transfers are then coordinated through the Los Angeles County Medical Alert Center.

Mercy personnel are treating patients from local medical facilities throughout Los Angeles County, according to officials. The LA Times reported previously that some patients were being transferred from nursing facilities as well.

Officials did not elaborate on how they think the coronavirus may have arrived on the Mercy, but Pfaff said that a “full contact investigation” was conducted in each case. Pfaff said those in close contact with the crew members were removed from the ship, tested and quarantined.

The ship is serving as a referral hospital for non-COVID-19 patients admitted to shore-based hospitals.

“We’re taking every precaution to mitigate the risk of inadvertent exposure to COVID-19 for the military treatment facility (MTF) and entire Mercy crew,” Pfaff said.

On Friday, officials previously announced that one crew member tested positive for the virus and was later transferred to an isolation facility.

The latest number of cases aboard the ship was first reported by the San Diego Union-Tribune.

The Mercy provides a full spectrum of medical care to include general surgeries, critical care and ward care for adults, according to the Navy.

The 1,000-bed ship is staffed by more than 800 Navy medical personnel and support staff, and 70-plus civil service mariners who operate and navigate the ship, load and off-load mission cargo, assist with repairs to mission equipment and provide essential services to keep the medical facility running.

Editor’s note: This story has been updated with more information on the patients being treated by Mercy personnel.

Stephanie Rivera is the community engagement editor. Reach her at [email protected] or on Twitter at @StephRivera88.