An American national on a US government repatriation flight has tested positive for hantavirus, and another passenger is showing mild symptoms, following a deadly outbreak on the MV Hondius cruise ship. The US Department of Health and Human Services says both are traveling in biocontainment units out of caution.

Upon arrival in the US, all 17 citizens on board will undergo clinical assessment at the University of Nebraska Medical Center. Seven other US passengers have already returned home and are being monitored.

The outbreak has killed three people-a Dutch couple and a German woman-who had sailed on the MV Hondius. The ship is currently docked in Tenerife, Spain. Officials say the risk of a major outbreak is very low.

The World Health Organization has recommended 42 days of isolation for those leaving the ship. However, acting CDC head Dr. Jay Bhattacharya said he does not want to cause public panic, noting human-to-human transmission is rare and should not be compared to COVID-19.

Meanwhile, French Health Minister Stéphanie Rist confirmed a French woman who returned from the ship has tested positive and is deteriorating in isolation in Paris. British and Spanish passengers are also under quarantine.