French Health Minister Stephanie Rist said on Tuesday that it was not certain whether the hantavirus strain involved in the outbreak on the MV Hondius cruise ship may have mutated, although officials were “rather reassured”.

“There are things … we do not know about this virus,” Rist told the National Assembly. “We do not yet have the complete sequencing of the virus, which allows us to say with certainty today, even if we are rather reassured to date … that this virus has not yet mutated.”

The French health ministry did not respond to a request for additional comment.

Hantavirus is primarily spread by rodents but can be transmitted between people in rare cases, according to the World Health Organisation. It usually begins with flu-like symptoms, such as fatigue and fever, one to eight weeks after exposure.

A cluster has been linked in recent days to the MV Hondius ship, which docked in Spain’s Canary Islands following a polar expedition that departed from Argentina.

The outbreak has been linked to the Andes strain of hantavirus, with officials consulting Argentina, where an outbreak involving the same strain ended in 2019.

The WHO has said there was no indication that there was anything unusual about the hantavirus strain on the ship beyond its location.

It has confirmed nine cases and urged isolation of suspected cases, adding that more are expected given passenger interactions before the virus was detected. However, it said there was no sign of a wider outbreak.

Italy to examine samples from quarantined man

Meanwhile, Italy’s top infectious diseases hospital said on Tuesday it would examine biological samples from a man in quarantine having come into contact with a woman who died of Hantavirus.

The ANSA news agency had previously reported that the man, a 25-year-old from the southern Calabria region, had been hospitalised.

He was briefly on the same plane as a woman who later died from the virus. The woman was disembarked from the KLM flight before it took off from Johannesburg.

ANSA reported earlier that the man was being transferred to the Spallanzani Hospital in Rome, but the hospital later clarified that it was only awaiting his biological samples in order to analyse them.