USS Fort McHenry
CNN  — 

A new case of a viral infection aboard a US navy warship was reported Tuesday, which means the USS Fort McHenry will continued to be quarantined at sea in the Middle East, according to the US Navy Fifth Fleet.

The new case means 26 sailors and Marines have fallen ill on board since December. The Navy said it is awaiting findings from a medical team before deciding when the ship can be deemed safe to pull into a port.

Last week CNN reported that the Fort McHenry had essentially been quarantined at sea for over two months and has been unable to make a port call due the outbreak of the mumps-like virus.

The 26 sailors and Marines aboard the amphibious warship have been diagnosed with parotitis, which causes symptoms similar to mumps, according to US military officials.

Until CNN asked about the incident, the US military had not disclosed it.

“None of the cases are life-threatening and all have either already made or are expected to make a full recovery,” the Fifth Fleet said in a statement provided to CNN last week.

All 703 military personnel aboard the ship have received measles, mumps and rubella (MMR) booster vaccinations, according to the US Navy’s Fifth Fleet headquartered in Bahrain.

The ship is currently operating in the Persian Gulf region and military medical officials are assessing when it may be deemed medically safe to make a port call.

A US military official told CNN that when there are major disease outbreaks, a decision may be taken to halt port visits until 30 days after the last reported illness due to varying incubation periods.

But the Fort McHenry did make a port call in early January in Romania when it was in the Black Sea before traveling back through the Mediterranean and into the Middle East.

After they became ill, the patients were quarantined and treated in the ship’s medical facility. Living and work spaces were disinfected.

None of the personnel had to be medevaced off the ship and all are expected to make a full recovery.

The ship, which carries Marines to perform amphibious warfare duties did have some of its scheduled training modified to deal with the outbreak’s impact.