Hantavirus: Canada expands monitoring, risk “remains low,” says PHAC

Canadian health officials say the risk to the public remains low, but authorities are intensifying monitoring and travel restrictions following a deadly outbreak of the Andes strain of hantavirus aboard the Dutch expedition vessel MV Hondius — an incident that has triggered a complex international containment effort after three passengers died and more than a dozen others fell ill.

In a media statement Tuesday (May 12), the Public Health Agency of Canada (PHAC) confirmed that four Canadian passengers connected to the outbreak safely returned to British Columbia on May 10 and were immediately placed under strict public health supervision.

The travellers, who remain asymptomatic, underwent health screenings at multiple stages of their return journey before being transferred to dedicated accommodations to complete mandatory self-isolation, said PHAC.

Local public health authorities are actively monitoring the group as part of a broader national response coordinated with international partners, including the World Health Organization (WHO).

READ MORE: Hantavirus – should the travel industry be worried? Travel advisors sound off

The outbreak aboard the MV Hondius, a polar expedition ship operated by the Netherlands-based Oceanwide Expeditions, has become one of the most serious known maritime outbreaks involving the Andes strain of hantavirus — a rare but highly-dangerous disease primarily associated with rodent exposure in South America and notable for its potential for limited person-to-person transmission.

Health officials say the quarantine period for the four Canadians could last up to 42 days.

The countdown began May 10, identified as the last day a confirmed case remained aboard the vessel.

Nine Canadians identified as high-risk contacts

PHAC said there are currently nine individuals in Canada considered high-risk contacts linked to the outbreak.

Two of those individuals had travelled aboard the MV Hondius, but disembarked on an earlier stop before the outbreak was first identified.

Three others may have been exposed during a flight involving a confirmed case. All remain asymptomatic and under monitoring, said PHAC.

Officials also clarified that one previously-identified contact in Quebec is no longer classified as high risk after updated assessments and revised WHO guidance.

Authorities warned the number of monitored individuals could continue to change as the investigation evolves.

International response intensifies

The outbreak has forced a multi-country evacuation and containment operation involving health agencies, airlines, border officials, and international public health authorities.

Under temporary Canadian measures, any passenger or crew member who has been aboard the MV Hondius since April 1, 2026, is prohibited from boarding flights to Canada, said PHAC.

The restrictions are being enforced in coordination with air carriers, public health authorities and border agencies, said the agency.

WHO guidance currently advises that all passengers, crew, and identified high-risk contacts avoid travel while under observation.

Symptoms of hantavirus can initially resemble influenza before progressing rapidly to severe respiratory illness.

Despite the unprecedented nature of the outbreak aboard the expedition vessel, Canadian officials stressed that the overall risk to the general public remains low.

“The Government of Canada will continue to monitor the situation closely and provide updates as needed,” PHAC said.

No sign of larger outbreak

After all passengers and a large portion of the crew were evacuated, the MV Hondius began its return voyage to the Netherlands, where the vessel is expected to undergo extensive cleaning and disinfection procedures.

The head of the WHO said all confirmed and suspected infections linked to the outbreak have so far been limited to passengers and crew aboard the cruise ship.

"At the moment, there is no sign that we are seeing the start of a larger outbreak," said Tedros Adhanom Ghebreyesus, WHO's director general, in a statement. "But of course the situation could change, and given the long incubation period of the virus, it's possible we might see more cases in the coming weeks."

Health officials believe this is the first recorded hantavirus outbreak aboard a cruise ship.

Although there is currently no specific cure or vaccine for hantavirus, the WHO says prompt diagnosis and early medical treatment can significantly improve a patient’s chances of survival.

“A rare but severe disease”

Prior to the outbreak, the MV Hondius, a 107.6-metre polar expedition ship with 80 cabins, was running a 24-day "Atlantic Odyssey" voyage.

The journey began in Ushuaia, Argentina, on April 1, 2026, and featured stops in remote, ecologically diverse South Atlantic and African locations before a medical emergency diverted the ship to Europe.

According to the WHO, illnesses began surfacing on board between April 6-28 and was characterized by fever, gastrointestinal symptoms, rapid progression to pneumonia, acute respiratory distress syndrome and shock.

Human hantavirus infection is primarily acquired through contact with the urine, faeces, or saliva of infected rodents, and symptoms usually show up between one and eight weeks after exposure.

“It is a rare but severe disease that can be deadly,” says the WHO.

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