Hantavirus: How Scary Is It??

Summary

---

Science Vs – “Hantavirus: How Scary Is It??”

Date: May 13, 2026
Host: Wendy Zuckerman
Guests: Dr. Neil Vora, Dr. Ann Sheehy, Prof. Michelle Harkins
Production: Spotify Studios

---

Episode Overview

Wendy Zuckerman tackles rising fears about a hantavirus outbreak on a cruise ship, asking: How dangerous is hantavirus, really? Could it be the next pandemic, or is panic outpacing reality? The episode pits Twitter freakouts and dire headlines against scientific evidence. Wendy interviews virologists and clinicians to break down what the virus does, how it spreads, and—crucially—whether we should actually be worried.

---

Key Discussion Points & Insights

1. The Cruise Ship Outbreak (00:00–03:44, 04:17–05:16)

• Setting: The MV Hondius cruise ship faced a deadly outbreak; 3 passengers died, 18 are under monitoring in the U.S., and at least 11 total cases identified.
  • “Something like 40% of people who get diagnosed with it will die. And scarier still… it feels like this hantavirus outbreak is weird because it’s spreading from person to person.” – Wendy (01:28)
• Social Fallout: News clips and social media react with Covid-19 deja vu.
  • “Everybody better wake the f*** up with this hantavirus bullshit. We’re not doing it again.” – Neil Vora (02:16)

2. What Happens If You Get Hantavirus? (04:17–10:16)

• Expert: Prof. Michelle Harkins, pulmonary & critical care physician, University of New Mexico.
  • Hantavirus infects the endothelial cells lining blood vessels and lungs.
  • Symptoms Progression:
    • Starts like the flu: fever, chills, body aches.
    • GI issues in the first week: nausea, vomiting, diarrhea.
    • Severe cases see “cytokine storms”—the immune system overreacting (07:12).
    • Lungs fill with fluid (“blood vessels become very leaky” – Harkins, 07:48), causing rapid respiratory decline.
    • Cardiac complications: possible cardiogenic shock.
  • Treatment: No antivirals or vaccine. ICU support, oxygen, and for severe cases, ECMO (“artificial lung”) is used as a stop-gap.
    • “Some of the first patients that I saw came in talking. They were on just a little oxygen and then rapidly deteriorated… were put on ECMO within four hours.” – Harkins (09:30)
• Unpredictability: “You can’t just tell by looking” who will get severely ill. Young, healthy patients can deteriorate quickly. (09:53)

3. How Do People Usually Get Hantavirus? (10:16–13:04)

• Reservoirs: Found worldwide (except Antarctica), mostly carried by rodents; also found in bats, moles, shrews.
• Common Transmission:
  • From contact with rodent feces or urine—cleaning up areas with dried droppings can “aerosolize” the virus.
    • “As you are sweeping and cleaning… dried up rat crap can kind of turn to dust, go up into the air and then you breathe that in…” – Wendy/Neil Vora (11:23–11:33)
  • Possible but less common: eating contaminated food.
• Usual Outcome: Most people never get severe symptoms; many are unaware of mild infection (about 2% in the Americas have antibodies—05:56).

4. The Andes Virus: Person-to-Person Transmission (13:04–15:06, 18:11–20:52)

• Mutation Matters: The cruise ship outbreak is linked to the Andes virus—the only known hantavirus strain to spread between humans.
  • “Andes virus is the only hantavirus… that spreads from one person to the next.” – Neil Vora (13:40)
• Outbreak History: Past Andean outbreaks, e.g., 2019 Argentina—birthday party and funeral events. Person-to-person spread was traced, but only among close contacts (21:36–21:59).

5. How Does the Andes Virus Spread Between People? (20:52–24:43)

• Virologist Insight: Prof. Ann Sheehy explains Andes vs. Sin Nombre viruses:
  • Glycoprotein (GP) on Andes virus enables broader cell infection and faster replication.
• Transmission Dynamics:
  • Spread is mostly via close contact (romantic partners, family).
  • Notably, deep kissing and sexual contact are identified as major risk factors.
    • “They defined it only as exposure to saliva… Other risk factors… sleeping in the same bed, having sex, and being exposed to semen.” – Wendy (23:16)
  • Virus has been detected in semen, even years post-infection (2023 study—23:55).

6. Is Hantavirus Highly Contagious? (24:43–26:12)

• Contagiousness/R₀: Compared to Covid or measles, hantavirus spreads far less easily.
  • “Even in the most… dramatic outbreaks we have, the R0 is something like 2 for hantavirus. And if you do any quarantining at all, it drops below one.” – Ann Sheehy (24:43)
• Why? The virus prefers blood vessel cells deep in the body, rather than the nose or throat—so coughing or breathing generally doesn’t expel lots of virus.

7. Context: Real-World Risk & Outbreak Limits (26:12–29:09)

• Prevalence in Reservoirs, But Low Case Rates:
  • In New Mexico, up to 25% of mice may carry hantavirus, but human cases are rare: fewer than 10 per year.
    • “Does that scare you?” – Michelle Dang
    • “Sounds high, but our case rates are really low… It’s not easy to get hantavirus.” – Prof. Harkins (27:20)
    • “I actually was bitten by a mouse in my house… But I did not get hanta. I got rat bite fever instead.” – Harkins (27:39)
• Symptomatic Transmission: You’re not likely contagious before showing symptoms—unlike with Covid (28:50).
  • “When it’s been documented well, it happens. And that person is sick…” – Ann Sheehy (28:50)

8. Mutation & Pandemic Potential (29:09–31:10)

• Mutational Stability: Andes virus has not meaningfully mutated in 30 years.
  • “Covid is a master mutator… But that’s not the case with hantavirus. …the sequences are virtually the same.” – Ann Sheehy (29:45)
• Pandemic Potential: All three experts are unequivocal: this is NOT the next pandemic.
  • “No, rest easy. This is not it… But I think we’re not going to see too many more cases.” – Ann Sheehy (30:40)
  • “This current outbreak of Andes virus, this hantavirus is not the next pandemic.” – Neil Vora (30:57, 31:06)
• Final Takeaway: Hantavirus, specifically Andes virus, can cause deadly disease, but outbreaks are small, transmission is limited, and mutation rates are minimal.

---

Memorable Quotes & Moments

• Wendy lays out internet hysteria:
  • “The Internet is freaking out.” (02:07)
• Dr. Harkins on the unpredictability:
  • “Some people come in and you’re like, oh my gosh, they’re going to get worse and they get better… then someone comes in that… you think a young, healthy-ish person… and they’re on the bypass machine the next day.” (09:53)
• Ann Sheehy’s relief for listeners:
  • “No, no, rest easy. This is not it. …there will be something that’s more serious. But no, this is… You can be okay.” (30:40)
• On real-life risk:
  • “Does that scare you?”
    – Michelle Dang
  • “Sounds high, but our case rates are really low. So it’s not a very easy virus to transmit.” – Prof. Harkins (27:20)
• On mutations:
  • “Covid is a master mutator… But that’s not the case with hantavirus.” – Ann Sheehy (29:45)

---

Important Timestamps

• 00:33–01:28: Cruise ship outbreak summary & fatality stats
• 04:47–10:16: Prof. Harkins explains infection’s course, symptoms, and treatment
• 11:09–13:04: Dr. Neil Vora details typical hantavirus transmission via rodents
• 13:40: Andes virus—the only hantavirus with human-to-human spread
• 18:11–19:10: Prof. Ann Sheehy reacts as a virologist to the cruise outbreak
• 21:36–23:55: Andes outbreaks—spread in close contacts; kissing, sex as risk factors
• 24:43–25:10: Ann Sheehy: R0 for Andes virus is low, “not gonna be an outbreak”
• 27:03–27:52: Case rates in New Mexico; Harkins’ own close call with a mouse
• 28:50–29:09: Sheehy: Transmission really only when visibly ill
• 29:45–30:13: Mutational stability of Andes virus
• 30:40–31:10: Universally: NOT the next pandemic—expert consensus

---

Final Takeaways

• Hantavirus can cause severe illness and death, especially the Andes strain, but outbreaks are rare and transmission is limited.
• Unlike Covid-19, it’s not highly contagious, hasn’t meaningfully mutated, and typically only spreads via close contact when people are symptomatic.
• Science dismisses the social panic: this is not the next pandemic.
• Practical advice: If you’re cleaning areas with rodent droppings, wear a mask. Don’t let pandemic trauma override facts.
  • “And if you have a friend that just got off a cruise ship, avoid deep kisses.” – Wendy Zuckerman (31:10)

---

Transcript

[Wendy Zuckerman]

Hi, I'm Wendy Zuckerman and this is Science Versus the show that pits facts against another frigging pandemic. Today on the show, Hunter Virus. There's been a lot of reports of an outbreak of a weird virus on the MV Hondius cruise ship.

[Neil Vora]

What began as a cruise of a lifetime has instead turned into a major

[Ann Sheehy]

medical mystery and an international crisis.

[Wendy Zuckerman]

Three people have died amid an outbreak of hantavirus on a cruise ship sailing the Atlantic. The first cases seem to have started with a husband and wife that boarded after a bird watching expedition. The couple ended up dying along with one other passenger. And over the next few weeks, more cases have started rolling out.

[Ann Sheehy]

French national has tested positive for hantavirus

[Wendy Zuckerman]

following her evacuation from the cruise liner MV Hondias. Now her condition is said to be deteriorating. 18American passengers from the hantavirus affected cruise ship are now being monitored at two facilities in the United States.

[Neil Vora]

One patient has tested positive and is

[Ann Sheehy]

now in a biocontainment unit in Omaha, Nebraska. Global health officials warning There are now 11 total cases of the deadly hantavirus. Adding that number could go up as the virus can incubate for 42 days.

[Wendy Zuckerman]

And one thing that's really worrying here is just how deadly this virus is. Something like 40% of people who get diagnosed with it will die. And scarier still, according to news reports. It feels like this hantavirus outbreak is weird because it's spreading from person to person.

[Ann Sheehy]

Experts are confirming there have been cases of a rare strain on the ship

[Wendy Zuckerman]

that can be transmitted between humans. Meanwhile, officials have been scrambling to track down some people who left the cruise ship before they knew Hunter virus was on board. No surprises. The Internet is freaking out.

[Neil Vora]

Hantavirus will spread. It absolutely will get worse.

[Ann Sheehy]

Why do they let the people off the boat? Why'd you let them off the boat?

[Wendy Zuckerman]

Why did you let them off the boat?

[Neil Vora]

Everybody better wake the up with this hantavirus bullshit. We're not doing it again. The hantavirus Hannah Montana virus. This is crazy. History is about to repeat itself. I have seen this film before. Covid19 I want to watch a new film, the Titanic. And I'm getting very, very anxious, very nervous. And they should have sank that mother shit while they had the chance.

[Wendy Zuckerman]

So today on the show, what is going on with Hunter virus? What happens if you get infected? How is it spreading? And how worried do we need to be here? Could this be the next pandemic? When it comes to Hunter Virus, there's a lot of people saying we're not doing it again. And then there's science. Science versus Hunter Virus is coming up just after the break. This episode of Science Versus is presented by Amazon Health AI. Guys, we gotta talk about your secret late night Internet searches. You know the ones. Bumpy leg, rash, hair loss, itchy bum. Trying to figure out your body by endlessly searching for answers. We all do it, but does it always work? Well, you could try Amazon Health AI. It can connect your symptoms with your medical history to offer personalized care 24. 7. So call off the search. Amazon Health AI is here. Healthcare just got less painful.

[Sponsor/Ad Voice]

This episode is brought to you by Adobe Firefly, the all in one creative studio with AI powered image and video generation built for today's creative process. Firefly helps you generate, edit and experiment fast because the asks aren't getting smaller and the timelines.

[Wendy Zuckerman]

Woo.

[Sponsor/Ad Voice]

Yeah, still tight. With all the best creative AI models in one place, Firefly brings your ideas to life. Learn [e-mail] Firefly.

[Wendy Zuckerman]

Welcome back. Today we're talking all about Hunter Virus. And this is the first time a lot of us have even heard of this virus. So we're gonna break down exactly what it is, starting with what happens if you get infected. Because on the cruise ship, the three passengers died within just a few days of their symptoms starting, which is very scary. So we wanted to know how things can escalate so quickly. And for this we called up Professor Michelle Harkins.

[Professor Michelle Harkins]

I am a pulmonary and critical care physician at the University of New Mexico,

[Wendy Zuckerman]

and she's treated dozens of hantavirus patients in the icu. And she told us that there are a couple of dozen different types of Hunter viruses that can infect humans. The one that Michelle generally sees in New Mexico is called the Sinombre virus, and it is a lot like the version that popped up on the cruise ship.

[Professor Michelle Harkins]

Yeah, they're in the same family. We can call them relatives.

[Wendy Zuckerman]

So if you get infected with hantavirus and you have all these viral particles in your body, they tend to attack and go after this specific type of cell.

[Professor Michelle Harkins]

So this virus likes a particular cell, the endothelial cell, and it lines all the blood vessels, it lines a lot of the cells in the lung.

[Wendy Zuckerman]

What happens from here is that your body starts to mount an immune response to get rid of this invader. And that's often when you can start to get sick in a way that Michelle says might feel pretty familiar at first.

[Professor Michelle Harkins]

So you feel like you have the flu. You're sick, you have fever, chills, body

[Wendy Zuckerman]

aches, headache, and it's possible that more of us have been infected with hantavirus than we think. Studies have measured the blood of thousands of people for hantavirus antibodies, Evidence that hantavirus had weaseled its way into their body, and then their immune system responded. And they found that in the Americas, just over 2% of people that they looked at had hantavirus antibodies. A lot of those folks were probably never diagnosed with hantavirus and might have had pretty mild symptoms. But for others who get infected, like some of the passengers on the cruise ship, it can get very nasty. In the first week of symptoms, you can start getting GI problems. So think stomach pain, nausea, vomiting, diarrhea. And in fact, more than half of the people who actually get diagnosed with hantavirus end up with severe symptoms. And that can happen because your immune system kind of gets completely carried away. It creates this massive inflammatory response and

[Professor Michelle Harkins]

cause, like, a war, if you will. There's a whole dysregulation of our immune system that is caused by this virus.

[Wendy Zuckerman]

This is called a cytokine storm. Cytokines are these small proteins that get secreted by your immune system, and they can go completely haywire during a hunter virus infection, where they can even start to attack your organs. The same thing can happen With a particularly nasty COVID infection, too. But the thing that sets hunter virus apart is what happens next. So as the hunter virus keeps attacking those cells that it loves, the endothelial cells, and particularly the cells that line vessels, that lining can start to break down.

[Professor Michelle Harkins]

The blood vessels become very leaky.

[Wendy Zuckerman]

This means the fluid in your blood vessels, the plasma, can now leach into places it's not meant to go, like your lungs, and fluid can start to build up there. If this happens, your lungs can't bring in enough oxygen, and patients will tell Michelle, hmm, I'm coughing, or I am.

[Professor Michelle Harkins]

I'm short of breath. I can't catch my breath.

[Wendy Zuckerman]

And at this point, things can start to go downhill really fast as your lungs just keep flooding with fluid.

[Professor Michelle Harkins]

That can all progress over a matter of, you know, three, four, six hours and get worse. If you enter this phase and you really don't seek medical attention, you, have over 50% chance of mortality, and you can die within 24 hours.

[Wendy Zuckerman]

Another thing that can happen here is called cardiogenic shock, and it's where your heart stops, Pump enough blood to get oxygen to your organs, and even if you seek medical attention, your chance of surviving isn't great. We don't have medicine specifically for hunter virus. Michelle told us that the only thing she can do is really, if you catch it early enough, you can put people on oxygen or even something called an ECMO machine. This is like an artificial lung where doctors take your blood out, put oxygen in it and then pump it all back into your body. Michelle told us that she'll hook people up to the ECMO basically to buy them some time while the virus runs its course. Michelle told us what it was like for some of her patients. She talked to producer Michelle Dang about it.

[Professor Michelle Harkins]

Some of the first patients that I saw came in talking. They were on just a little oxygen and then rapidly deteriorated and were put on ECMO within four hours. And it was striking that it can progress that fast.

[Michelle Dang]

Can you see that, like when you look at a patient who's already come in or expect how they might handle the disease?

[Professor Michelle Harkins]

No, it is really difficult. Some people come in and you're like, oh my gosh, they're going to get worse and they get better and they're off of oxygen in a day or two. And then someone comes in that is, you know, you think a young, healthy, ish person that comes in and they're on 2 liters of oxygen and then they're on the bypass machine the next day. So it's. You can't just tell by looking.

[Wendy Zuckerman]

So that's part of what makes Hunter virus so scary. It can sneak up on you and you can get sick really fast and even die and there's no vaccine to prevent it. So you me, we don't want to get a nasty case of Hunter virus. How do people get infected in the first place? Now, Hunter virus is actually found all over the world. We've seen it in on every continent except Antarctica. It's often carried by rodents, but it's also found in animals like bats, moles and shrews. And usually just zooming out from the cruise ship outbreak here, people get infected because they come into contact with poo or wee from an infected rodent. We talked about how this can happen with Neil Vora. He's a doctor who studies spillover diseases from animals to people.

[Neil Vora]

So, you know, in other scenarios in which we've seen people get infected with hantaviruses is that they're living in areas where rodents are also living right now. Maybe someone is then grooming in their house and they're sweeping all these rodent feces.

[Wendy Zuckerman]

And as you are sweeping and cleaning the house, any dried up rat crap can kind of turn to dust, go up into the air and then you

[Neil Vora]

breathe that in and you're aerosolizing dust and Viral particles at the same time from that feces, and then the person can get infected. Right? So that's one possible route of exposure.

[Wendy Zuckerman]

This virus can also survive stomach acid and potentially infect you if you eat food that's contaminated with, say, little bits of rat poo. The World Health Organization estimates that worldwide, thousands of people get hunter virus every year, but they usually infected with a version that's less deadly than the one on the cruise ship. And we think that the vast majority of these infections worldwide come from direct contact with, say, rodent feces. But with the outbreak on the cruise ship, something different seems to be unfolding. So we think that maybe the first infection, patient zero, got exposed this way that we've just described through aerosolized rat crap dust. He is Neil again.

[Neil Vora]

So we don't know for sure how the first person got infection. Right now, the leading theory is that this person got infection while in Argentina bird watching. And bird watching is a very safe activity, but somehow they might have interacted with the feces, for example, of a rodent or rodent urine, maybe got a bite from a rodent, but that's less likely. And then they got infected. But this is right now working theory, but it's highly plausible.

[Wendy Zuckerman]

Now, one or two people getting Hunter virus directly from breathing in rodent poo or pee. This is not surprising because, like we said, hunter virus is around rodents in a lot of places, including Argentina. What's weird is that most of the time, when someone gets huntavirus from a rodent, it stops with them. Most types of hunter virus cannot spread from person to person, except the version of hantavirus that showed up on the cruise ship. It's called the Andes virus, and it can.

[Neil Vora]

Andy's virus is the only hantavirus that we know of that spreads from one person to the next.

[Wendy Zuckerman]

And that is probably exactly what happened on the cruise ship. And something that's worrying a lot of people right now is that we might not know everyone who's been infected. Because this virus, it can hang around your body for a while before you start showing any symptoms. Producer Michelle Dang asked Professor Michelle Harkins

[Michelle Dang]

about this right after someone breathes in that dust with the hantavirus from mouse poo, what happens next?

[Professor Michelle Harkins]

They may just go on their merry way, and then there's an incubation period. And unfortunately, it can be from one to eight weeks. Typically, we see people within about two weeks afterwards, but there are studies showing that it can last up to eight weeks.

[Wendy Zuckerman]

Eight weeks. That means, theoretically, some of the people who were on the boat and then left without being quarantined could be infected right now, wandering around, breathing, coughing, listening to podcasts. So after the break, could this lead to the next pandemic coming up?

[Sponsor/Ad Voice]

Are you looking for support in your weight management journey? Zepbound Tirzepatide may be able to help. Zepbound is a prescription medicine used with a reduced calorie diet and increased physical activity to help adults with obesity or some adults with overweight who also have weight related medical problems to lose excess body weight and keep the weight off. Zepbound is Approved as a 2.5, 5, 7.5, 10, 12.5 or 15mg injection. Zepbound contains Tirzepatide and should not be used with other Tirzepatide containing products or any GLP1 receptor agonist medicines. It is not known if Zepbound is safe and effective for use in children. Don't share needles or pens or reuse needles. Don't take if allergic to it or if you or someone in your family had medullary thyroid cancer or if you've had multiple endocrine neoplasia Syndrome Type 2. Tell your doctor if you get a lump or swelling in your neck. Stop Zepbound and call your doctor if you have severe stomach pain or a serious allergic reaction. Severe side effects may include inflamed pancreas or gallbladder problems. Tell your doctor if you experience vision changes before scheduled procedures with anesthesia. If you're nursing pregnant, plan to be or taking birth control pills. Taking Zepbound with a sulfonylurea or insulin may cause low blood sugar. Side effects include nausea, diarrhea and vomiting, which can cause dehydration and worsen kidney problems. Talk to your doctor, call 1-800-545-5979 or visit zepbound Lilly.com

[Wendy Zuckerman]

this episode is brought to you by Amazon Health AI. Hey there, it's me, Wendy. Before this podcast continues, I'll need you to fill out 37 forms about your listening history. Oh wait. Just kidding. That would be ridiculous. Yet we do it every time we need healthcare. But new Amazon Health AI is different. It can connect your health history to offer personalized care so that you can get help fast. Amazon Health AI Healthcare just got less painful.

[Michelle Dang]

This episode is brought to you by Prime Obsession is in session, and this summer, Prime Originals have everything you want. Steamy romances, irresistible love stories, and the book to screen favorites you've already read twice off Campus Elle every year after the Love Hypothesis, Sterling Point and more slow burns Second chances chemistry you can feel through the screen. Your next obsession is waiting. Watch only on prime. Ready to soundtrack your summer with Red Bull Summer All Day Play. You choose a playlist that fits your summer vibe the best. Are you a festival fanatic, a deep end dj, a road dog, or a trail mixer? Just add a song to your chosen playlist and put your summer on track. Red Bull Summer All Day Play. Red Bull gives you wings. Visit RedBull.com BrightSummer ahead to learn more. See you this summer.

[Wendy Zuckerman]

Welcome back. Today on the show, Hunter virus. How freaked out do we need to be? So here's where we're at right now. We know that this virus has the potential to spread from person to person. And now the question is, how quickly can it spread? Could this lead to the next pandemic? And to find out more, we called up Professor Ann Sheehy, a virologist and immunologist at the College of the Holy Cross in Massachusetts. She's a friend of the show we've had her on before. And Ann told us that when she heard about this Hunter virus outbreak, I wasn't happy.

[Ann Sheehy]

So as virologists, you never like hearing about a virus that is doing something unusual.

[Wendy Zuckerman]

On top of that, she was like, and it's happening on a cruise ship

[Ann Sheehy]

that's traveling all around the world with passengers from all around the global community who are then going to disperse. That's not a good setup. You're like, oh, no.

[Wendy Zuckerman]

Oh, no. I don't want my virologist saying, oh, no. But don't worry, because by the end of this episode, you'll be thinking, oh, yes, because you'll know more science. And that's always great. Okay, so as we mentioned, this version of Hunter virus that's roaming around the cruise ship is the only one we know that can transmit from person to person, which makes it different. So the one that we heard about from the doctor, Michelle, which was called Sinombre. So Anne told us that to understand what makes the Andes version capable of spreading, we can compare the two.

[Ann Sheehy]

So let's, let's take Andes versus Sinombre. So if you were to look at those two hantaviruses, those are, they're pretty highly related, but there's regions that are a little bit different between Sonambre, which doesn't spread human to human, and Andes, that does.

[Wendy Zuckerman]

One difference is in a protein that sits on the outside of the virus and helps it to break into cells in our body.

[Ann Sheehy]

So for coronavirus, for analogy, we think about Spike, right The spike protein. So on Andy's virus, instead of they don't have spike, we call it glycoprotein.

[Wendy Zuckerman]

So, gp, if you think about the cells in your body, like a house with a tiny little door, GP is the key that allows Hunter virus to open that door, break into our cells, and infect us.

[Ann Sheehy]

So these GP proteins are a little bit different on Andes virus. And the consequences, at least on the sort of infection level, is the Andes virus can infect a wider range of cells.

[Wendy Zuckerman]

One study found that the Andes virus also seems to replicate faster in, say, heart tissue compared to other versions of Hunter virus. So potentially, when you get infected with this Andes version, there's just more viral bits in your body and you have a higher viral load, which could then increase the chance that you go on to infect someone else. And we have examples from other outbreaks that illustrate how this can all play out. So in Argentina, back in 2018-2019, we saw one of the biggest Andes virus outbreaks ever recorded. Scientists think that it started when one person got exposed to the virus the usual way from a rodent, and then

[Ann Sheehy]

so went to a birthday party, was feeling symptomatic, but, you know, birthday party went and looks like at that birthday party probably exposed some other people, but at least two other people that went on to then be involved in social events and spread. And one of them was the wake event, the second person that had died.

[Wendy Zuckerman]

Yeah. So it spread at the birthday party, someone died from that infection, and then at their wake, other people got infected. Ultimately, researchers tracked 34 cases, and 11 people died. Scientists were able to trace this all pretty well and even test people's blood. And they found that those who had more virus inside their body was. Were more likely to spread the Andes virus to other people. But what's interesting is that we don't actually know exactly how the virus is spreading from person to person. Is it through coughing, through breathing, through touching? Scientists think that, generally speaking, you see really close contacts having a higher chance of spreading it to each other. So not just someone you're passing at the supermarket, say. And we know this, for example, from a study on a cluster of people who got infected in Chile. And they found that sexual contact was a big risk factor for spreading it. And in particular, the paper references deep kissing. That was one of the biggest risk factors they found. And they mentioned deep kissing a lot. They defined it only as exposure to saliva. I guess that is. That is what deep kissing is at the heart of it. Other risk factors in that study were sleeping in the stomach, same bed, having sex and being exposed to semen. And on this point we found another study from 2023 that tracked a 55 year old man who got infected with the Andes virus and later recovered. But get this, almost six years later, traces of the virus could still be found in his semen. Now, I think this is probably going to make this type of Hunter virus sound really scary, right? It can spread from person to person. It could stay in semen for all these years. But it's really important to compare how contagious this virus is to other viruses out there that you know and love, like Covid and measles. So remember the R0 from the height of the COVID pandemic, this is basically the number that scientists calculate to say if you get disease X, how many susceptible people will you pass it onto on average? And for some diseases, this is super high, like measles, famous for being incredibly contagious if you're not vaccinated. It's estimated that if you get it, you could give it to 12 to 18 other people. But for this Hunter virus.

[Ann Sheehy]

So I think even in the most sort of the most dramatic outbreaks we have, the R0 is something like 2 for hantavirus. And if you do any quarantining at all, it drops below one. And once an R naught drops below one, it's not gonna be an outbreak. You're not gonna get sustained spread. So I think we're very fortunate that this virus does not spread easily from person to person.

[Wendy Zuckerman]

This might be partly because Hunter virus doesn't seem to hang around in your nose, throat and lungs in the same way that Covid and influenza does. You know, where a big breath could push out a bunch of viral particles into the air and, you know, maybe infect the person you're talking to instead. Hunter virus likes to stick around deeper in the cells of our lungs because it really likes those endothelial cells inside our blood vessels. And the fact that this type of Hunter virus doesn't spread that easily from person to person is probably why the largest outbreaks that we've had of it have gotten just a few dozen people sick. Even with this cruise ship outbreak, so far at least, it's hardly gone bananas. In over a month so far, we've had about a dozen people infected. Now in this outbreak, it's worth pointing out that while there were early reports that a woman got infected after just sitting on a plane near someone who was on the cruise ship and later died of hantavirus, it now Looks like that's not true. The woman on the flight later tested negative. So here's where we are at. Hantavirus, when you compare it to other scary and contagious viruses, it does not spread easily from person to person. But also your chance of getting a nasty case of hantavirus from a rodent is also pretty low. Michelle, who's our doctor from New Mexico, who's seen how devastating Hunter viruses can be, and she lives in a place where the rodents can be infected with Hunter virus and people every now and then get infected. So Michelle, Dang, our producer, asked her,

[Michelle Dang]

do you freak out every time that you see a mouse?

[Professor Michelle Harkins]

No, I don't. You know, we actually have done trapping campaigns, and about 25% of the mice in New Mexico carry hantavirus.

[Michelle Dang]

It sounds pretty high, though. Does that scare you?

[Professor Michelle Harkins]

Sounds high, but our case rates are really low. So it's not a very easy virus to transmit. And that's like a key thing. It's not easy to get hantavirus. I actually was bitten by a mouse in my house because my cat chased it in.

[Michelle Dang]

Oh, no.

[Professor Michelle Harkins]

And I tried to catch it and release it, and it was bit by the mouse. And I was like, great, I'm gonna get Hanta. But I did not get hanta. I got rat bite fever instead.

[Wendy Zuckerman]

So she took antibiotics for the rat bite fever. She's totally fine. But the broader point is that even though there's a lot of mice scurrying around New Mexico carrying this virus, pooing and weeing all over place, and around 2 million people live there, doctors diagnose fewer than 10 cases a year. Ann, our virologist, told us that there might be something else working in our favor here too. Although we mentioned before the break that Hunter virus can have this long incubation period where you can have two months between getting infected and showing symptoms, which, yes, is a long time, even Anne said, this is crazy to me. But she also said that unlike Covid, it's not clear that you can actually spread the disease during that time. So here's Anne.

[Ann Sheehy]

It appears, at least from the, you know, scant evidence that we do have from well analyzed outbreaks, it appears that most of the time, transmission, when it's been documented well, it happens. And that person is sick. Like they are visibly sick, they have a fever. They are not well.

[Wendy Zuckerman]

And with all of the bonkers stuff on social media that makes this sound so scary, I'm gonna give you one more comforting thing. This version of Hunter virus that led to the relatively Small outbreak on the cruise ship. It's been known to science since 1996, 30 years ago, when Macarena was number one on the charts. And in that time, three decades, it really hasn't mutated, particularly when you compare it to viruses that have caused pandemics.

[Ann Sheehy]

Covid is a master mutator, much like influenza. That's their bread and butter. That's how they survive. But that's not the case with hantavirus. They looked at the Andy's virus that circulated in 2018 in this outbreak, and they compared it to another outbreak that had been documented in 1996, so 22 years previously, and the sequences are virtually the same.

[Wendy Zuckerman]

So put it all together. This virus does not spread easily between people, which is why when an odd outbreak has happened before, it doesn't tend to blow up. And so far, this virus hasn't been mutating to become better at transmitting between people. So when we asked Ann the big question of this episode, the question that so many of you guys had, is this gonna be the next pandemic? Here's what she said.

[Ann Sheehy]

No, no, rest easy. This is not it. Get ready. Cause there will be. There will be something that's more serious. But no, this is not. This is. You can be okay, but I think we're not going to see too many more cases.

[Wendy Zuckerman]

And other researchers that we spoke to said the same thing.

[Neil Vora]

I want to be very clear. This current outbreak of Andy's virus, this hantavirus is not the next pandemic.

[Professor Michelle Harkins]

No, this is not the next pandemic.

[Neil Vora]

So, yeah, it's not the next pandemic.

[Wendy Zuckerman]

And I know you might be feeling, hey, some of you scientists said Covid would be fine too, and look what happened. I hear you, but it's easy to forget that Covid was a completely new virus when it just landed on our doorstep in 2019. And at the beginning of the pandemic, scientists were making educated guesses about what was going on and how the virus was going to behave. And they got stuff wrong with this Hunter virus that's causing the outbreak. The Andes version. Scientists have been studying it for 30 years, and we know that scary outbreaks tend to be pretty small. But still, if you want to be careful, if you're cleaning up a space that might have rodent poo, wear a mask. And if you have a friend that just got off a cruise ship, avoid deep kisses. That's science verses. This episode has more than 80 citations in it. If you want to read more about Hunter virus, understand where we get all of our information from. There's a link to our transcript in the show notes. Go check it out. This episode was produced by Michelle Dang with help from Blythe Terrell, Meryl Horn, Rose Rimler, Aketti Foster Keyes and me, Wendy Zuckerman. We're edited by Blythe Terrell. I'm the Executive Producer. Fact checking by Diane Kelly Mix and sound design by Bobby Lord Music written by Bobby Lord, Bumi Hidaka so Wiley, Emma Munger and Peter Leonard. Special thanks to the researchers we spoke to for this episode, including Professor Glenn Marsh. Science Versus is a Spotify Studios original. You can listen to us for free on Spotify or wherever you get your podcasts. If you are listening on Spotify, you can you can write a comment. We read them all and nice ones are very, very nice. It also helps the show to grow, keeps our bosses happy. So write us a nice comment. Also, you can follow us and tap the bell icon so you get notifications when new episodes come out. I'm Wendy Zuckerman. Back to you next.

[Sponsor/Ad Voice]

Spring just slid into your dms.

[Wendy Zuckerman]

Grab that boho look for that rooftop dinner, those sandals that can keep up with you. And hang some string lights to give your patio a glow up. Spring's calling, Ross.

[Sponsor/Ad Voice]

Work your magic.