The ministry stressed that the hospital was “prepared to deal with such cases, is able to care for the patient, and guarantee the safety of staff and all patients”.

“There is currently no risk to the Swiss public.”

According to the statement, the man returned from a trip to South America with his wife at the end of April, “after travelling on the cruise ship on which there were a number of hantavirus cases”.

The MV Hondius has been at the centre of an international alert since Saturday, when the UN health agency was informed that three passengers had died and the suspected cause was hantavirus — a rare disease usually spread from infected rodents typically through urine, droppings and saliva.

The Dutch-flagged ship set sail from Ushuaia in Argentina on April 1 and has been anchored off Cape Verde since Sunday.

The Swiss ministry did not say when the man being treated in Zurich had left the ship.

It said he had “noticed symptoms” after returning, and had contacted his doctor and then had gone to the USZ for further assessment.

“A test that was carried out at the reference laboratory at the Geneva University Hospitals (HUG) revealed a positive result for hantavirus,” it said, adding that “it concerns the Andes virus” — the only strain of hantavirus that can be passed between humans.

It stressed that “transmission only occurs through close contact”.

The ministry said it “therefore considers the occurrence of further cases in Switzerland unlikely” and the patient’s wife had not shown symptoms, but was “self-isolating as a precaution”.

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