Canada has been informed of 26 travellers who shared a flight with a person potentially infected with hantavirus, Chief Public Health Officer Dr. Joss Reimer revealed on Thursday.
Provincial and territorial health authorities are attempting to contact those people now. Reimer said European authorities had designated those travellers as “no risk” of infection, but that Canada is taking a more cautious approach.
Canadian public health authorities consider those travellers to be “minimal, low risk” contacts, said Reimer.
It’s the latest update from Canadian officials who are working to uncover the full scope of a fatal outbreak that began on board the MV Hondius, a cruise ship that docked in Spain’s Canary Islands on Sunday.
The total number of people in that “low risk” category is now 27, Reimer said. Health Canada is not requiring those people to self-isolate, but provincial requirements may vary.
There are nine “high-risk” individuals, including former cruise passengers and their close contacts. They’ve been instructed to isolate, and all remain asymptomatic.
Reimer said there is no conclusive evidence to show hantavirus can be caught from an asymptomatic patient. Hantavirus, at this stage, does not pose a pandemic risk.
Canada may test contacts
Health Canada is not offering tests to high- or low-risk asymptomatic contacts, Reimer also said on Thursday. That may change pending guidance from international partners and an advisory group assembled to inform Canada’s handling of the outbreak.
For now, tests are not being offered because “the literature is not as well established” for hantavirus detection in asymptomatic patients. If anyone starts to show symptoms, they’ll be offered a test.
Inaccurate testing brings its own risks, Reimer said, because of “the false reassurance that a negative result can provide.”
“If somebody is, perhaps, testing negative but later could go on to develop hantavirus, I don’t want that individual to be taking their isolation requirements less seriously. That is the balance we are trying to strike,” she said.
Why not isolate everyone?
The incubation period can stretch up to eight weeks, but epidemiologist and cardiologist Dr. Christopher Labos says the average timeline to develop symptoms is around two weeks.
CTV News asked Labos why Health Canada would not opt to ask everyone who may be infected to isolate, just to be safe.
“This is not a very easily transmissible virus,” he responded, adding it appears health authorities made a calculated decision not to disrupt peoples’ lives for six to eight weeks when the likelihood of their infection is so low.
“Hantavirus is nowhere near as infectious as COVID-19 was,” he said.
