A French woman and an American national evacuated from the cruise ship at the centre of a deadly hantavirus outbreak have tested positive for the virus, as the complex operation to repatriate those onboard continued on Monday.

The French woman was one of five French passengers who disembarked from the ship in Tenerife on Sunday before being flown to a hospital in Paris.

The French health minister, Stéphanie Rist, said the woman was in a serious condition on Monday. Rist said the woman had started to feel very unwell on Sunday night and “tests came back positive”. Rist told France Inter radio: “Unfortunately, her symptoms worsened overnight.” She is being treated in a specialised infectious diseases unit of a hospital in Paris.

An American passenger who was flown to Nebraska along with 16 others on Sunday evening also tested positive but had no symptoms. The US health department said one American national evacuated from the ship had tested positive for the Andes strain – the only hantavirus strain that is transmissible between humans – and another had “mild symptoms”.

Personnel in full-body protective gear and breathing masks began escorting the travellers from ship to shore in Tenerife in the Canary Islands on Sunday, in an effort that was continuing on Monday. More than 100 people of 23 nationalities are being evacuated in less than 48 hours, in an operation described by Spanish authorities as “complex” and “unprecedented”.

Spain’s health ministry said on Monday that “all possible measures had been adopted from the start in order to cut possible chains of transmission”, adding that passengers underwent a health check and had their temperatures taken when the ship arrived off Tenerife on Sunday.

It also said the French woman who had developed a fever on the evacuation flight had not had a high temperature when she was examined onboard the MV Hondius.

Three passengers from the MV Hondius – a Dutch couple and a German woman – have died and others have fallen sick with the rare disease, which usually spreads among rodents.

No vaccines or specific treatments exist for hantavirus, which is endemic in Argentina, from where the ship departed in April.

But health officials have said the risk for global public health is low and have played down comparisons with the Covid-19 pandemic.

Rist said 22 more contact cases had been identified among French nationals, including eight people who had travelled on a 25 April flight between Saint Helena and Johannesburg, and 14 more on a flight between Johannesburg and Amsterdam.

The Dutch woman who died was on the flight to Johannesburg and later briefly boarded a flight to Amsterdam but disembarked before takeoff.

Health authorities in several countries have been tracking passengers who had already left the ship, plus anyone who may have come into contact with them.

The French prime minister, Sébastien Lecornu, was due to hold a meeting of medical advisers and ministers on Monday afternoon to follow the issue.

The French government spokesperson, Maud Bregeon, told BFMTV that it was important not to spread a sense of “panic”. She said: “We’re following the situation with the greatest vigilance, on the basis that it is a virus that we know, that a 42-day isolation period has been decided and the objective remains the same: protecting the French people.”

The repatriation operation had evacuated 94 people of 19 different nationalities on Sunday, said the Spanish health minister, Mónica García.

Of the 54 people who remained aboard – 22 passengers and 32 crew – 28 will disembark today and evacuate on a Dutch flight to the Netherlands. The MV Hondius will then depart for the Netherlands with the 26 crew members.

García said a second plane that was to fly passengers back to Australia would not be coming to Tenerife because of timing problems, and that all the remaining passengers would now be evacuated on the Netherlands flight.

The captain of the MV Hondius has praised the crew and passengers for their behaviour on the ship.

“I’ve decided to take this time to thank every single guest and crew member onboard here, as well as our colleagues back home,” Jan Dobrogowski said in a video message.

“The past few weeks have been extremely challenging to us all. What touched me the most, what moved me the most, was your patience, your discipline, and also [the] kindness that you showed to each other throughout.”

Passengers wearing blue medical suits began disembarking the Dutch-flagged vessel on Sunday to reach the small industrial port of Granadilla on Tenerife. They boarded Spanish army buses and travelled to Tenerife South airport in a convoy before boarding their repatriation flights.

The World Health Organization recommends a 42-day quarantine and “active follow-up”, including daily checks for symptoms such as fever, the UN body’s lead for epidemic and pandemic preparedness and prevention, Maria Van Kerkhove, said in Geneva.