Cruise ship hantavirus outbreak not a cause for concern in Saskatchewan: Microbiologist

A microbiologist says a hantavirus outbreak on a cruise ship shouldn’t be a cause for concern in Saskatchewan.

Dr. Joseph Blondeau, a clinical microbiologist and the head of clinical microbiology at Royal University Hospital and the University of Saskatchewan, joined The Evan Bray Show on Monday to discuss the outbreak of hantavirus on a cruise ship now anchored in the Canary Islands.

Read more:

• Experts say hantavirus unlikely to be next pandemic
• What to know about hantavirus, the illness linked to a cruise ship outbreak
• 2 passengers test positive for hantavirus as a third shows symptoms after cruise ship evacuation

Listen to the full interview with Blondeau, or read the transcript below:

The following transcript has been edited for length and clarity.

EVAN BRAY: Should people be concerned?

DR. JOSEPH BLONDEAU: I don’t think so. I think what we’re looking at here was a really unfortunate situation where a couple of individuals happened to go to an endemic area where the vector, or the rodent which carries this particular virus, is known to exist. Don’t know what the nature of their exposure was that would have exposed them to the virus, but it looks like the Dutch couple in particular may have been exposed prior to getting on the ship, and then sort of brought this virus onto the ship when they boarded, and then departed for the excursion that they were on.

This virus is a little bit different than other hantaviruses that are found around the world, because this is the only hantavirus – at least that I’m aware of – that has been associated with human-to-human transmission. The hantavirus that we have here in Canada is not, and there are 38 different strains of hantavirus around the world, and this one here is the only one that’s associated with human-to-human transmission. And even that association is under circumstances of a very, very close contact. And that close contact would be anything to do with sharing of a bed or intimate contact or very close contact when you’re caring for a patient that may have this virus. But in terms of of this virus becoming something analogous to what we saw with COVID, that’s not going to happen.

The MV Hondius cruise ship is anchored at a port in Praia, Cape Verde, Wednesday, May 6, 2026. (AP Photo/Misper Apawu)

Can we go back to just this basic understanding of where hantavirus comes from, where it originates, and how we are most at risk of being infected?

BLONDEAU: Hantavirus is a virus which is commonly found in rodents. And in this province, in Saskatchewan, we see it in deer mice and rice rats and white-footed mice, cotton rats, etc. And the virus is shed from these rodents in urine and feces, and it’s also in their saliva. And so how humans get exposed is that is if you actually come in contact with the rodent or the rodent’s droppings when you’re cleaning, say, a shed or a barn or whatever. If you start sweeping this stuff up, then the virus can become aerosolized. You inhale it, and then you can become infected.

And the difficulty with sometimes tracing these cases is that the incubation period can be quite long. Some of the literature says one to six weeks. Some says one to eight weeks, which is why some of the people coming off this ship are going to be quarantined for extended periods of time, just because it can have a prolonged incubation time.

Is there a correlation, Dr. Blondeau, between the severity – and by severity, I mean the lethality of a virus – and the ease in which it can be transmitted? Because our understanding is that it’s not good if you get this strain of hantavirus. It’s quite dangerous to you, could be life threatening. Does that, though, kind of counterbalance with how easily it’s transmitted?

BLONDEAU: No, it does not. Unfortunately, humans are accidental hosts for this virus, simply because this is not a virus that we would normally carry nor share between humans. So, as I said, we become infected when we come into contact with its source, and that’s from rodents. I think that the uniqueness of this virus is that in patients that do become infected, it does have a high mortality rate. The mortality rate can be as high as 50 per cent, some literature says 38 to 40 per cent, and it probably has to do more with the fact that when this virus starts causing infection in the body, it gives you some early symptoms that you can confuse with some other type of infections. You could get things like fatigue and fever and muscle aches, etc. And then you may have this progressive period where you start to see more severe symptoms, including severe respiratory distress, shortness of breath and even leading to shock. That, in and by itself, does not correlate with the ease with which this virus may be transmitted from one person to another. That’s something entirely different.

When we think back to the days of COVID and if we think of viruses like measles and mumps, etc., we know that these viruses are very, very easily transmitted by aerosolization. That means once we get infected with them, our respiratory secretions contain this virus for a period of time. We liberate that into the air. Anybody that happens to be standing close to us, we can potentially expose. The same is not necessarily true for the hantavirus strains in general, which is why you need very, very close and sustained contact – particularly with this Andes strain – in order for you to acquire the virus from somebody else. So it’s a very, very rare event. So no, the severity of the disease and the ease of transmission are not related.

I have a text actually on the line from a fellow saying he was ripping apart an old shed on the weekend and found a nest that looked like an old nest that belonged to some mice. His dog was in there chewing it apart. Should he be concerned that his dog had this contact? What does that look like for pets, and is that a threat to humans?

BLONDEAU: I don’t know. Because I’m not a veterinarian, I don’t know what the risks are for companion animals like dogs and cats. But certainly he himself, if he was ripping apart this old shed, and if it was in a confined space, and a confined space where he was doing something that could potentially aerosolize a virus, then there’s a potential risk. But then it assumes the fact that the virus was actually present, and we don’t necessarily know that every time we see a mouse or mouse droppings, there’s actually viable virus that’s present. And so there are a number of factors that would have to fall into place before a person actually gets infected with this virus. So we have to keep in mind, Evan, that that this is a very rare infection indeed. I think last week, when we had talked about it, I had said that there’s only been one hundred and some odd cases across the country over the last number of years. And the cases seem to be adjusted more to the west, because we have the vector that’s here. But when we look at the population sizes in western Canada, and we look at the rodent population and our interactions, or potential interactions, this is a very, very rare infection indeed, and it’s not something, I don’t think, that people need to be overly concerned about.

And take those precautions that we’ve been talking about. If you’re going to be cleaning sheds and whatnot, if you think you see mouse droppings, take a bleach solution, a one-in-10 bleach solution, sort of spray the area, let it sit for 10 to 15 minutes before you try and clean it up, because the virus does have an envelope, and we know that detergents and bleaches degrade the envelope, and once that occurs, then the virus is no longer infectious. And don’t be vacuuming if you’ve not sprayed down the area. Wear masks, wear some gloves, that sort of stuff, and all of those things will further reduce the likelihood of being exposed.

In summation, your thoughts on the seriousness of this and the the impact, the worry that people in the province of Saskatchewan should have?

BLONDEAU: I think this is a very, very unfortunate event that occurred with these folks on this cruise ship, and it’s sad that people have died from it. But it is not an overall risk to the general population. And I think if we do what we’ve always been doing in this province, and being careful when we’re cleaning our sheds and barns and whatnot, then I think our risks are very, very low.