Washington: The U.S. Department of Health and Human Services said on Sunday that one of the 17 Americans being repatriated from a hantavirus-struck luxury cruise ship has tested mildly positive for the Andes strain of the virus, while a second has mild symptoms.

All the U.S. citizens are being airlifted to the United States, and the two passengers with symptoms are travelling in the plane's biocontainment units, HHS added. The second symptomatic passenger has not yet been confirmed as having the virus.

Hantaviruses are a group of viruses that are usually spread by rodents, but in rare cases can be transmitted from person to person. Health authorities have said the risk of the virus spreading is low.

Eight people no longer on the MV Hondius have fallen ill, according to a World Health Organization update from Friday, with six of them confirmed to have contracted the virus. A Dutch couple and a German national have died.

The Andes strain of hantavirus, identified in the ship's outbreak, can cause severe lung illness that can be fatal in up to 50% of cases, according to the WHO.

The U.S. State Department's airlift will transport passengers to the ASPR Regional Emerging Special Pathogen Treatment Center (RESPTC) at the University of Nebraska Medical Center in Omaha, Nebraska, and the passenger with mild symptoms will be taken to a second RESPTC, HHS said.

On arrival at the facilities, each individual will undergo clinical assessment and receive care based on their condition, HHS added.

Spain and France have evacuated their citizens from the MV Hondius, which is anchored near Tenerife, the largest of the Canary Islands, officials said. Australia, Canada, the Netherlands, Turkey, the UK, and Ireland are also flying home nationals who were on the ship.

US citizen tests positive for hantavirus as cruise ship outbreak raises concerns