Hantavirus has reached Canadian soil — here is what employers need to understand

Canada's connection to the world's most closely watched infectious disease outbreak began quietly. Two passengers who disembarked the MV Hondius at St. Helena on April 24 — before the outbreak was publicly declared — returned home to Ontario. A third Canadian, from Quebec, shared a Johannesburg-bound flight with a confirmed case. By the time Chief Public Health Officer Dr. Joss Reimer briefed reporters on Friday, the number of Canadians linked to the outbreak had grown to ten, all asymptomatic and self-isolating. Four more, repatriated from Tenerife on Sunday, are now isolating in B.C. under daily monitoring by provincial health teams.

The outbreak — a cluster of Andes hantavirus infections aboard a Dutch expedition cruise ship that departed Ushuaia, Argentina, on April 1 — has killed three people and infected at least eight across 23 nationalities.

"At this time, the overall risk to the general population is low. Onward spread within Canada is not expected, even if an infected individual were to arrive here," Reimer said. "However, given the rarity of this virus, it is important that we take a precautionary approach."

For Canadian employers and HR leaders, that precautionary instinct is worth sharing.

What makes this outbreak different

Hantavirus is not new to Canada. The National Microbiology Laboratory has confirmed 168 cases since surveillance began in 1994, averaging roughly five a year, concentrated in Saskatchewan, Alberta, B.C. and Manitoba — almost all caused by the Sin Nombre virus, spread through contact with infected deer mice, not between people.

The Andes strain is different. "In Canada, we do not have the species of hantaviruses that are known to transmit from human to humans," says David Safronetz, chief of special pathogens at PHAC and an adjunct professor at the University of Manitoba. "Those are exclusive to South America — primarily only the Andes virus strain."

The disease begins with flu-like symptoms but can progress rapidly to severe respiratory failure. The CDC puts the mortality rate for serious cases at approximately 38 per cent. Crucially, the virus can incubate for up to six weeks, which makes monitoring returning travellers genuinely difficult.

Even so, the workplace risk is low. "This virus transmits very inefficiently human to human — you do really need prolonged and close contact," Safronetz said. The greater risk is to household members, not colleagues in a shared office.

Legal obligations and a recent precedent

Low risk does not mean no obligation. Across Canadian jurisdictions, employers must take every reasonable precaution to protect workers' health and safety — and that duty does not stop at the office door.

Read more: Employer required to accommodate immunocompromised employees during communicable disease outbreaks

A 2025 Ontario Human Rights Tribunal decision, covered by HRD Canada, found that an employer failed its duty to accommodate an immunocompromised worker during a communicable disease outbreak — raising health concerns three times was enough to trigger the accommodation process. Remote work and modified duties should have been offered. The decision is a reminder that infectious disease is an accommodation question as much as a safety one.

Under Ontario's Occupational Health and Safety Act, occupationally acquired illnesses must be reported to the WSIB within three days. The Canada Labour Code imposes equivalent duties on federally regulated employers.

Read more: Canada introduces 10 days of paid sick leave

What employers should do now

The risk is low and employer communications should say so plainly. Beyond that, four proportionate actions are appropriate:

Review travel advisories for South America. Employees heading to Argentina, Chile or neighbouring countries for field work, natural resource projects or ecotourism should be briefed on PHAC's precautions — avoiding rodent contact, using wet-cleaning methods in rural settings, and seeking medical attention promptly if symptoms develop after travel.

Update your infectious disease response plan. A COVID-era plan written for airborne respiratory spread may not address a pathogen with a six-week incubation window. Review and revise accordingly.

Brief managers specifically. General all-staff communications are not enough. Managers need clear guidance on what to do if an employee discloses potential exposure — including leave handling, team communication, and the limits of what they can ask under privacy law.

Audit your sick leave framework. Canada entered COVID-19 with most provinces lacking paid sick leave. Most emergency measures have since expired. If an employee needed to isolate for up to six weeks and would lose income as a result, your organisation has both an ethical and a legal risk to address. HRD Canada has covered the case for robust sick leave as an infection-control mechanism — it remains unresolved.

Ten Canadians did not expect to come home to self-isolation when they set out on or near the MV Hondius. A rare but deadly pathogen, a six-week incubation window, and a response spanning three provinces and four federal departments is precisely the kind of event that tests whether infectious disease preparedness is real or theoretical. Canadian workplaces should not need a similar surprise to find out.