France has confirmed its first case of hantavirus in a passenger evacuated from the MV Hondius, the luxury cruise ship at the center of an international outbreak that has already claimed three lives.

The patient, a French woman, tested positive after developing symptoms during her repatriation flight from Spain’s Canary Islands to Paris on Sunday. Her condition “unfortunately deteriorated overnight,” according to French Health Minister Stephanie Rist.

She was one of five French nationals flown home from the ship. The other four tested negative but remain in isolation for at least 15 days, with authorities prepared to extend that period.

The confirmation marks a troubling escalation in the hantavirus outbreak linked to the MV Hondius. The ship, which carried nearly 150 passengers and crew, has been stranded and rerouted amid fears of human-to-human transmission of the Andes strain — one of the few hantaviruses capable of spreading between people.

French authorities have also identified 22 other French nationals who were on earlier flights connected to the ship and are monitoring them closely. In Germany, four passengers were transferred to a hospital in Frankfurt for observation, while a German woman remains in stable condition in Düsseldorf.

Spain, which accepted the ship in the Canary Islands, has declared May 6 as “day zero” for quarantine purposes, potentially requiring up to 42 days of isolation for those on board. The ship was expected to depart Monday evening for the Netherlands after final disembarkation operations.

This development turns what was already a frightening situation at sea into a broader public health concern now reaching into Europe. A virus that typically spreads through rodent droppings has now shown its ability to move between humans in the close quarters of a cruise ship — and is following passengers home.

The fact that the infected French woman developed symptoms during the evacuation flight raises questions about how many others may have been exposed during the frantic efforts to get people off the vessel. With an incubation period that can last several weeks, health officials across multiple countries are bracing for potential additional cases in the coming days.

While authorities stress the overall risk to the general public remains low, this outbreak has exposed serious vulnerabilities in how remote expedition cruises handle health emergencies — and how quickly a rare pathogen can cross borders in our connected world.

The MV Hondius was supposed to be a journey of adventure. For some passengers, it has become a journey into uncertainty and fear.