Spanish medical staff in Tenerife, Canary Islands, accompany one of the final remaining passengers to be evacuated from the MV Hondius, which was affected by a hantavirus outbreak, May 11.Chris McGrath/Getty Images
Many people across Canada are learning about hantavirus for the first time because of an outbreak aboard a cruise ship that has killed three people, gaining worldwide attention.
But hantavirus is not a new disease.
Nor does it have “pandemic potential” despite fears that this outbreak is the start of the next COVID-19. Hantavirus, unlike COVID-19, does not transmit easily between people and does not appear to be rapidly mutating.
Ten Canadians are currently isolating across the country due to potential exposures on the MV Hondius cruise ship or planes with infected passengers. None are symptomatic and public health officials have stressed that they do not believe further spread will occur.
Some of the final remaining passengers wait on the dock after being evacuated from the MV Hondius.Chris McGrath/Getty Images
Hantavirus is a rare but severe disease that humans can acquire through the inhalation of virus particles from rodent urine, droppings or saliva. The initial infection is believed to have been acquired by a passenger during a birdwatching excursion in southern Argentina before boarding the ship in April.
Lynora Saxinger, an infectious-diseases specialist at the University of Alberta, spoke to The Globe and Mail about the evolution of hantavirus and why Canadians should not be worried.
This interview has been edited and condensed for clarity.
When was hantavirus first identified globally?
It was first identified as a virus in the 1970s in Korea near the Hantan River. It was found to be the cause of Korean hemorrhagic fever. The disease itself had been recognized for some time, but the ability to identify the virus only really happened in the late 1970s.
It wasn’t until the 1990s when there was an outbreak in the southern United States, in the Four Corners region [where Arizona, Utah, Colorado and New Mexico meet]. It’s actually kind of a funny story. They were initially going to call it Muerto Canyon virus but the people who lived there said no. Then they tried to name it after a First Nations reserve, or something, and they said no. And so they called it Sin Nombre, which actually means no name.
The Sin Nombre virus is the one that most people in infectious disease and public health would be familiar with in the context of North America.
When did Canada report its first case of hantavirus and how prevalent is it now?
The virus was first recognized in B.C. in 1994 but the earliest known case was in Alberta in 1989. They actually looked back and tested it. There’s been around 150 or so cases in Canada since we’ve been aware of it and tracking.
Passengers are screened with a temperature scanner before boarding a plane bound for Canada, at the airport in Tenerife.Arturo Rodriguez/The Associated Press
The prevalence varies from year to year, and in the U.S. too, it’s the same story. It really depends on how people are interacting with rodents, because there’s probably some infected deer mice around in many places across Canada at any given time, particularly in rural locations. And it just entirely depends on if you happen to inhale aerosolized urine or feces.
Most cases are in Asia and Europe.
How deadly is hantavirus and how can people protect themselves? Is it treatable?
If you’re unlucky enough to acquire hantavirus, there is a considerable risk of severe illness and possible death. The quoted mortality numbers are up to 50 per cent but I think in our actual experience, at least in the cases I’ve seen here, it is less than that. But it’s still very serious. It’s an ICU stay.
If you know or think you have deer mice and you’re going to be sweeping out your shed, for example, I would say you should probably spray the area down with a bleach solution before you get in and start sweeping.
If you do get hantavirus, it’s all supportive care – oxygen, blood pressure support, respiratory support with ventilation. It’s a fearsome disease if you get it.
What should people know about the Andes strain linked to the cruise ship outbreak?
The Andes strain is a major outlier among the hantaviruses. Canadians would not be expected to be exposed to this unless they were on that cruise ship, literally.
The very extreme difference between the Andes strain and the strains causing disease elsewhere in the world is that it does seem to spread person to person. That’s a big red flag in terms of why the international public health community is taking this very seriously. Usually, hantavirus isn’t really a public health issue.
Should Canadians be worried about the current outbreak?
Honestly, no. I think that people should remain attentive and, if you’re interested, remain interested, but I don’t think that people have to worry.
It remains a very focal problem related to a cruise ship, which are places that are always problematic for any introduced infection that can spread person to person because they’re such tight quarters.
The head of the World Health Organization (WHO) said on Tuesday there was no sign of a broader hantavirus outbreak, though further cases could emerge, as officials continue to monitor passengers from an affected cruise ship.
Reuters