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What's That Rash?
Hantavirus: what we know about the cruise ship outbreak
00:13:43
A cruise ship at the centre of a virus outbreak — sound familiar? Passengers and crew are beginning to disembark the MV Hondius after several cases of hantavirus sent them into quarantine. The virus is usually caught through contact with infected rodent urine, droppings or saliva. Transmission between humans is rare. Norman and Tegan answer common questions about the hantavirus, and how it compares to the handling of COVID-19.
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- [00:01]
A
Morning decisions. How about a creamy mocha Frappuccino drink? Or sweet vanilla smooth caramel maybe? Or white chocolate mocha? Whichever you choose, delicious coffee awaits. Find Starbucks Frappuccino drinks wherever you buy
- [00:14]
B
your groceries, ABC Listen, podcasts, radio, news, music and more.
- [00:22]
C
So you might think you're listening to watch that rash, but you're actually listening to the first episode of Hantecast.
- [00:29]
B
Oh my gosh, don't wish that upon us. This actually is the old coronacast feed. If you're subscribed to what's that rash? And we're going back to our roots today because we are talking about a viral outbreak. It's Norman and Tegan. We're here for a bonus episode of what? Yeah, fine, fine, fine. Let's call it Hantacast.
- [00:45]
C
Why not indeed. And we're not going to be talking about bats, we're going to be talking about rats.
- [00:51]
B
Aha. Exactly. So, okay, let's start with some basics. Briefly, Norman, what is hantavirus? Where does it come from? What's going on here?
- [01:01]
C
Well, nobody knew it existed probably until probably 50 years ago or so. And it's called hantavirus because the first outbreak, known outbreak to Western medicine, should I say, was along the Hantan river, hence Hanta, Hantan river in Korea during the Korean War, 3000 or thereabouts. United nations troops came down with a hemorrhagic fever, so fever, bleeding, and it also affected their kidneys and they got kidney failure and a high percentage of them died. So several hundred of them died. And it's thought that in fact they might have taken the virus, the American troops might have taken the virus back to the United States. So people didn't know what it was. You had this outbreak of this mysterious disease which affected thousands of troops and it caused a fair bit of panic and consternation. There was no known treatment and it took a controversial Nobel laureate called Carlton Gajrechek. He wasn't a Nobel laureate in those days, who in fact was the person who elucidated Kuru, the brain disease in Papua New guinea, along with Western Australian researchers. But he was the one who actually isolated the hantavirus and was the first person to do so and discovered what it was. And in fact, this was not a new disease. It had been there for centuries, if not thousands of years along the banks of the river and the Hantan River. Almost certainly the local people had some immunity to this disease because it was an ancient disease in that area. But you've got these non immune troops coming in stirring up the land with their tanks and camping and goodness, what else they were doing, stressing the rodents, mice in that area, and they caught the disease from the mouse droppings. So that was the first known outbreak of hantavirus in terms of Western medicine.
- [03:00]
B
And the reason we're talking about it now is because there has been an outbreak of hantavirus on a cruise ship, the MV Hondias. The outbreak was first described in South America. What was sort of the original presentation of this outbreak.
- [03:13]
C
Norman, let me just go back a little bit before I go jump into this, because what I didn't say there was. Since the discovery of the original hantavirus, it's now known as a family of viruses which exist in different parts of the world. In the United States, it tends to be in a pulmonary form rather than a hemorrhagic form.
- [03:31]
B
So are your lungs.
- [03:32]
C
Yep. And it looks as though that's what Gene Hackman's wife died of.
- [03:37]
B
Oh, yes.
- [03:38]
C
So it's a nasty disease which can be rapidly fatal. And the Andean version is a respiratory disease which looks as though it can spread human to human. Well, in fact, it can spread human to human. The other hantaviruses don't convincingly spread human to human. The Andean version of the virus does seem to spread human to human, but inefficiently it doesn't do it. It's not like measles or coronavirus or influenza where you've got large percentage of people who come in contact with the virus getting infected and then passing it on to others.
- [04:12]
B
So when you're saying the Andean version of the virus, is that what we're dealing with with this outbreak in the cruise ship at the moment?
- [04:17]
C
That's what's being reported, yes. Now, not a lot's known about it. They talk about a six week. You might have read a six week incubation period before the symptoms come out. But there have also been reports that it could be down to a few days. So there's a wide var in what is thought to be the incubation period and nobody's really quite sure what the infectivity period. So remember from coronavirus, there was a period where you caught the infection, then there was a period where you were infectious and then your symptoms came out and then it took a while for the virus to go away and stop being infectious. That pattern is really not known very well for the Andean version of the hantavirus or indeed any hantavirus. But let's assume that it's six weeks, several people on board the boat have caught it. And again, going back to coronavirus, although this is not a virus with high pandemic potential, unless it's had a mutation, it doesn't seem to have is they've all been living on this boat. And as we know from coronavirus days, it was being in the same room, breathing in the same dirty air or atmosphere as other people. It was how you caught the virus in the same household, in the same ward, in a hospital, and in the same enclosed environment with transportation. So here are all these people on a boat, presumably with the windows closed, not much ventilation, and they're breathing in the virus and it's not surprising that a reasonable number have become infected.
- [05:44]
B
So when, when I saw that it was on a cruise ship, it made me kind of wonder whether. Because it brought to mind the Ruby Princess in 2020, which was a big cluster of COVID But I wondered whether maybe there was something about cruise ships that either made a viru. Made more hospitable conditions for a virus to spread in. But I also wondered whether it was maybe a good thing. You've got people who are contained, they're not necessarily going off and away, they're contained. And maybe that helps more with tracing and with isolation.
- [06:14]
C
Yeah, in this case, you've got a small ship, small population on that ship, you know where they've been. Although there is some concern that there may have been contacts outside the ship when people have been put ashore that they're not too certain about. But the reality is it doesn't seem to be a very efficiently spread virus. The risk is much more to the individual themselves, particularly. This is a group of people who are older, because older, richer people are the people who can afford to go on these expensive cruises, and therefore their immune systems are less efficient to start with. So I think there's no evidence that this has high pandemic potential. But it's unknown, it's mysterious and people do get worked up about it.
- [06:54]
B
And understandably, I think we're all a bit scarred from COVID to one extent or another. But it also really brings to mind those early days of that pandemic where there's so many factors that we don't understand. And depending on where this virus falls on various spectrums, like how infectious is it? Does it transmit from human to human, how long's the incubation period? All of those things, depending on where it drops on that spectrum, has really big downstream effects. I know that, Norman, you predicted back in the 90s a potential hantavirus pandemic. What was this based on?
- [07:28]
C
I don't think I predicted a hantavirus pandemic. So I did a series called Invisible enemies for Channel 4 UK and SBS. I think it went away in 1990 and it was about the history of pandemics and how it affected human history. And I actually covered the hantavirus, Hantan fever. I think we interviewed Carlton Godicek from memory about it. And we predicted that there were likely to be outbreaks of hantavirus, particularly in continental United States, because the virus had almost certainly been taken back by American troops to the United States. So there hadn't been descriptions of hantavirus outbreaks. But indeed, over time, outbreaks of pulmonary hantavirus have been reported in the United States with significant mortality rates.
- [08:20]
B
So now people are being repatriated back to their home countries, including here, to Australia and to New Zealand. They're going to go into 42 days of quarantine, a really long time. But actually kind of brings us back to the original meaning of the word quarantine.
- [08:34]
C
40 days. Holding the boats off the coast of Venice or Genoa for 40 days to see whether or not the plague would work its way through. Look, experts are going to be dealing with this. They know what they're doing. The fact of the matter is a lot of these people are well into that 42 day period. And whether or not they need to be isolated for the full 42 days will be a matter of debate. Also whether or not you need to be quarantined in hospital or whether you could actually at home, because you're not talking necessarily about a virus that's going to be highly infectious.
- [09:09]
B
The thing with this outbreak is it's caused serious enough disease that three people have lost their lives and we shouldn't lose sight of that. And I think it reminds us of our vulnerability to diseases and we can't always predict where they're going to come from. What does this episode tell us about our ongoing risk of epidemics and pandemics in general?
- [09:29]
C
Pandemics arise from infections that we catch from animals, particularly viruses. And that's because we are not immune. We haven't got immunity to these animal infections. So an influenza pandemic is going to come from pigs or birds and then transmitted to humans and have a high mortality rate in humans. And so it is here with hantaviruses. Hantaviruses come from animals and spread to us. Luckily, it's isolated and it doesn't spread that easily, human to human, a bit like avian flu. At the moment where there have been isolated infections of humans, but no evidence of human to human infection, which we're lucky about because it has a higher mortality rate in individuals, not every individual, but in individuals who catch that influenza virus. So you can have, even in potentially highly infectious viruses like influenza, you can have variants of that virus which don't transmit easily from human to human, but if they do, then you've got a serious problem on your hands. Hantavirus does not seem to mutate as quickly as flu and that's why people say it doesn't have pandemic potential unless, unless there's been a mutation. But, but we're not seeing anything particularly surprising in this cruise ship because they've been isolated for weeks on end.
- [10:54]
B
Ok, so Norman, one of the things that you and I got accused of during the coronavirus pandemic was fear mongering. And I wonder where we can sort of place this in terms of being informed, being alert, but not alarmed. Help me put some context around this.
- [11:09]
C
Context for governments is we're exposed to zoonotic diseases, animal diseases all the time, and some of them are serious. In this case, serious enough to cause a reasonably high fatality rate, luckily not with pandemic potential. We have not got together as a world, in terms of the nations of the world to control zoonotic diseases or at least be aware of them and intercept outbreaks. That's the first thing. Second thing here is this is not one for us to panic about. It's not one that's going to spread throughout Australia because people are coming back. The risk is to the individuals themselves. And it just shows you the complexity of respiratory viral diseases where you've got to have a virus that knows how to attack humans, knows how to get into our cells, knows that, you know, can reproduce in high enough numbers to pass on to other people. You know, it's very good at survival. This is not one of those viruses, at least as we can see it at the moment. So it's not something to panic about, but it is something to be aware about, is that as we travel, as we go around the world, as we do more exciting things in more remote locations, we are going to expose ourselves to viruses that the locals may be pretty good at fending off, but we are not because we are vulnerable. So we just got to be alert to that fact.
- [12:33]
B
Well, that has been a little special bonus episode for you. We will be back with a normal episode of Whatsat Rash on Wednesday. We are going to be talking about muscle training, so make sure you don't miss that.
- [12:43]
C
See you then, Sam.