Hantavirus: How Scary Is It?? – Science Vs podcast
Chapter 1: Hantavirus shows up on a cruise ship
Hi, I’m Wendy Zukerman, and this is Science Vs, the show that pits facts against another friggin pandemic?? Today on the show: Hantavirus.
There’s been a lot of reports of an outbreak of a weird virus on the MV Hondius cruise ship[1] ...
What began as a cruise of a lifetime has instead turned into a major medical mystery and an international crisis.
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 …
A French national has tested positive for hantavirus following her evacuation from the cruise liner MV Hondius. Now her condition is said to be deteriorating.
18 American passengers from the hantavirus-affected cruise ship are now being monitored at two facilities in the United States[2]
One patient has tested positive and is now in a biocontainment unit in Omaha, Nebraska.
Global health officials warning there are now 11 total cases[3] of the deadly hantavirus, adding that number could go up as the virus can incubate for 42 days.
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.[4][5][6][7][8] And scarier still, according to news reports – it feels like this hantavirus outbreak is weird because it’s spreading from person to person[9] …
Experts are confirming there have been cases of a rare strain on the ship that can be transmitted between humans
Meanwhile officials have been scrambling to track down some people who left the cruise ship before they knew hantavirus was onboard[10] … No surprises – the internet is freaking out.
[Internet people]
Hantavirus will spread, it absolutely will get worse
Why did they let the people off the boat?? Why did you let them off the boat?? WHY DID YOU LET THEM OFF THE BOAT
Everybody better wake the fuck 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've seen this film before, Covid-19, I want to watch a new film - The Titanic, and I'm getting very, very, anxious, very nervous, and they should have sank that motherfucking ship when they had the chance
So today on the show, what is going on with hantavirus? 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 hantavirus there's a lot of people saying…
We're not doing it again!
And then there's Science.
Science Vs hantavirus is coming up — just after the break.
BREAK
Chapter 2: What happens if you get sick with hantavirus?
Welcome back! Today we’re talking all about hantavirus — and this is the first time a lot of us have even heard of this virus… So we’re going to 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,[11] which is very scary. So we wanted to know how things can escalate so quickly.
And for this, we called up Prof. Michelle Harkins[12] ...
MH I am a pulmonary critical care physician at the University of New Mexico
And she’s treated dozens of hantavirus patients in the ICU.[13][14] And she told us that there are a couple of dozen different types of hantaviruses that can infect humans[15][16] … the one that Michelle generally sees in New Mexico is called the Sin Nombre virus[17]. And it is a lot like the version that popped up on the cruise ship[18] …
MH: Yeah, they're in the same family. We can call them relatives.
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.
MH: 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.
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 …
MH: So you might feel like you have the flu. You're sick, you have fever, chills, body 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've found that, in the Americas, just over 2% of people that they looked at had hantavirus antibodies[19]… A lot of those folks were probably never diagnosed with hantavirus.. and might have had pretty mild symptoms[20] … 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[21][22]. And in fact, more than half of the people who actually get diagnosed with hantavirus — end up with severe symptoms[23] … And that can happen because your immune system kind of gets completely carried away… it creates this massive inflammatory response…
MH: It can cause like a war, if you will.[24] … it's a whole dysregulation of our immune system that is caused by this virus.
This is called a cytokine storm[25] … Cytokines are these small proteins that get secreted by your immune system and they can go completely haywire during a hantavirus infection[26], where they can even start to attack your organs. The same thing can happen with a particularly nasty Covid infection too[27].
But the thing that sets hantavirus apart is what happens next… so as the hantavirus keeps attacking those cells that it loves… the endothelial cells… and particularly the cells that line our blood vessels ... that lining can start to break down[28][29].
MH: the blood vessels become very leaky[30],[31]. …
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 in there … If this happens, your lungs can't bring in enough oxygen, and patients will tell Michelle …
MH: "Hmm, I'm coughing," or, "I am-- I'm short of breath. I can't catch my breath."
And at this point, things can start to go downhill really fast … as your lungs just keep flooding with fluid.
MH: That can all progress over a matter of, you know, three, four, six hours, uh, and get worse. … if you enter this phase, uh, and you really don't seek medical attention, you have over a 50% chance of mortality[32], and you can die within 24 hours[33].
Another thing that can happen here is called cardiogenic shock, and it’s where your heart stops pumping enough blood to get oxygen to your organs[34].
And even if you seek medical attention… Your chance of surviving isn't great[35][36][37]. We don't have medicine specifically for hantavirus[38], Michelle told us 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[39], this is like an artificial lung[40] 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
MH: 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.
MD: Can you see that, like, when you look at a patient who's already come in or, or expect what-- how they might handle the disease?
MH: No. It is really difficult. Some people come in and you're like, "Oh my gosh, they're gonna get worse," and they get better and they're off of oxygen in a day or two, and then someone comes in that is, uh, you know, you think a young healthy-ish person that comes in and they're on two liters of oxygen and then they're on the bypass machine the next day. So it's, you can't just tell by looking.
So that’s part of what makes hantavirus 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 do not want to get a nasty case of Hantavirus. Which leads to our next question: How do people get infected in the first place?
Chapter 3: How does hantavirus spread?
Hantavirus is found all over the world… we’ve seen it on every continent but Antarctica[41] … it’s often carried by rodents… But it's also found in animals like bats, moles and shrews[42]... 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,[43] he’s a doctor who studies spillover of diseases from animals to people …
NV 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 brooming in their house, and they're sweeping all these rodent feces …
And as you are sweeping and cleaning the house, any dried up rat crap can kind of turn into dust, go up into the air… and then you breathe that in.[44].
NV 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.
This virus can also survive stomach acid[45], and potentially infect you if you eat food contaminated with, say little bits of rat poo[46][47]. The WHO estimates that worldwide, thousands of people get hantavirus every year – but they’re usually infected with a version that is less deadly than the one on the cruise ship.[48] And we think the vast majority of these infections come from direct contact with, say, rodent feces.
But with the outbreak on this cruise ship, something different seems to be unfolding. So we think maybe the first infection, Patient Zero, got exposed this way that we’ve just described, through aerosolised rat crap dust. Here's Neil again.
NV 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 birdwatching[49][50][51] 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.
Now, one or two people getting hantavirus directly from breathing in a rodent poo or pee… not surprising. Because, like we said, hantavirus is around rodents in a lot of places, including Argentina[52].
What's weird is that most of the time, when someone gets hantavirus from a rodent, it stops with them. Most types of hantavirus cannot spread from person to person. Except the version of hantavirus that showed up on the cruise ship … which is called the Andes Virus … and it can[53][54].
NV: Andes virus is the only hantavirus that we know of that spreads from one person to the next.
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 about this.
MD: Right after someone breathes in that dust with the hantavirus from mouse poo[55], what, what happens next?
MH: They may just go on their m-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[56][57].
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 …[58]
So after the break — could this lead to the next pandemic??
Coming up.
BREAK
Chapter 4: How good is this hantavirus at spreading?
Welcome back. Today on the show: Hantavirus … 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[59] … 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 hantavirus outbreak …
AS: Um, I wasn't happy. So as a virologist, you never like hearing about, a virus that is doing something unusual.
On top of that – she was like… And it’s happening on a CRUISE SHIP?
AS: That’s traveling all around the world with, with passengers from all around the global community who are then gonna disperse, that that's not a good setup. You're like, "Oh, no."
Oh no?! I don't want my virologists 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.
Ok so as we mentioned, this version of Hantavirus that's roaming around the cruise ship is the only one we know that can transmit from person to person … Which makes it different to the one we heard about from the doctor, Michelle, called Sin Nombre. So Ann told us, to understand what makes the Andes version capable of spreading – we can kind of compare the two.
AS: So let's, let's take Andes versus Sin Nombre, 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 Sin Nombre, which doesn't spread human to human, and Andes, that does.[60]
One difference — is in a protein that sits on the outside of the virus … and helps it break into cells in our body …
AS: So for coronavirus, for analogy, we think about spike, right? The spike protein? So yeah, so on, on Andes virus, instead of, they don't have spike. We call it glycoprotein, 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 hantavirus to open that door, break into our cells and infect us…[61]
AS: So these GP proteins are a little bit different on Andes virus, and the consequence is, at least on the sort of in- infection level, is the Andes virus can infect a wider range of cells[62]...
One study found that the Andes virus also seems to replicate faster in, say, heart tissue … compared to other versions of hantavirus[63]. So potentially, when you get infected with this Andes version, there's just more viral bits in your body – and with a higher viral load – which could then increase the chance you go on to infect someone else.
And we have examples from other outbreaks… that illustrate how this can all play out. In Argentina back in 2018 to 2019[64] … 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 …
AS: So went to a birthday party, was feeling symptomatic, but, you know, birthday party.[65] 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 of the, the second person that had died.
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[66] … 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 were more likely to spread this Andes virus to other people[67] …
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 of a cluster of people who got infected in Chile and they found that sexual contact[68] 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 what deep kissing is at the heart of it.
Other risk factors in that study were sleeping in the 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 (RNA) could still be found in his semen!![69]
Now I think this is probably gonna make this type of hantavirus really scary… it can spread from person to person… it can stay in semen for all these years … but it's really important to compare how contagious this virus is to other viruses out there … viruses that you know and love, like Covid and measles…
So, remember the R-naught from the height of the Covid pandemic? This is basically the number scientists calculate to say: if you get disease X, how many susceptible people will you pass it on to, 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[70] … but for this hantavirus …
AS: So I think even in the most, sort of the most dramatic outbreaks we have, the R0 is something like two[71] for, for hantavirus. And if you do any quarantining at all, it drops below one. And once, once an R0 drops below one, you're not gonna, 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.
That might be partly because Hantavirus doesn't seem to hang around in your nose, throat and lungs in the same way that Covid and influenza does[72][73] … y'know where a big breath could push a bunch of viral particles out into the air and y’know, maybe infect the person you’re talking to.
Instead, hantavirus 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 hantavirus doesn’t spread that easily from person to person is probably why the largest outbreaks we've had of the Andes Virus have just a few dozen people getting sick ... even with this cruise ship outbreak, so far at least it’s hardly gone bananas[74].In over a month, so far we’ve had about a dozen people infected?
Now, in this outbreak, worth pointing out, while there were early reports that a woman got infected after just sitting on a plane,[75][76] 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.[77]
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, our doctor from New Mexico, has seen how devastating hantavirus infections can be, and lives in a place, where every now and then people get infected directly from rodents so producer Michelle Dang asked her …
MD: Do you freak out every time that you see a mouse?
MH: No, I don't. Uh, you know, we actually have done, uh, trapping campaigns and about 25% of the mice[78] in, uh, New Mexico carry hantavirus.
MD: It sounds pretty high, though. Doesn’t that scare you?
MH: 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. Uh, it's not easy to get hantavirus. I actually was bitten by a mouse in my house because my cat chased it in
MD Oh no
MH And, uh, I tried to catch it and, and release it and I was bit by the mouse and I was like, "Great, I'm gonna get hanta.” But I did not get hanta. Um, I got rat bite fever instead, so …
She took antibiotics for the rat bite fever, she’s totally fine. But even though there's a lot of mice scurrying around New Mexico carrying this virus … pooing and weeing all over the place … and around 2 million people[79] live there, doctors diagnose fewer than 10 cases a year[80][81] …
Ann, our virologist, told us that there might be something else working in our favor here too … Although - we mentioned before the break – that hantavirus 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 Ann said
AS: 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 Ann.
AS: I, it, 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.[82]. They are not well
And with all of the bonkers stuff on social media that makes this sound so scary, I’m going to give you one more comforting thing. This version of Hantavirus that led to the relatively small outbreak on the cruise ship, it’s been known to science since 1996[83] – 30 years ago, when Macarena was number 1 on the charts.[84] And in that time, 3 decades … it hasn't really mutated … particularly when you compare it to viruses that HAVE caused pandemics …
AS: COVID is a master mutator, Uh, 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 Andes 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 were virtually the same.[85]
Chapter 5: Is this hantavirus going to cause the next pandemic?
So you 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, the virus isn't mutating to become better at transmitting between people … so when we asked Ann – the big question of the episode… the question that so many of you guys had… Is this gonna be the next pandemic? Here’s what she said.
AS: No. No. Rest easy. This is not it. Get ready, um, 'cause there will be, there will be something that's more serious, but no, this is not... This is... You can be okay. Um but I think we're not gonna see too many more cases.
And other researchers we spoke to said the same thing …
NV: I wanna be very clear: this current outbreak of Andes virus, this hantavirus, is not the next pandemic.
MH No. This is not the next pandemic
GM: So yeah, it's not the next pandemic
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 that pandemic scientists were making educated guesses about what was going on how the virus was gonna behave, and they got stuff wrong … with this hantavirus that’s causing the outbreak … the Andes version … scientists have been studying it for 30 years and we know the scary outbreaks tend to be pretty small – But 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 Vs
We’ve got more than 80 citations in this episode … you can find them at the link to our transcript in the show notes.
This episode was produced by Michelle Dang, with help from Blythe Terrell, Meryl Horn, Rose Rimler, Ekedi Fausther-Keeys and me, Wendy Zukerman. 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 Wylie, Emma Munger and Peter Leonard. Special thanks to the researchers we spoke to about this, including Prof. Glenn Marsh.
Science Vs is a Spotify Studios Original. Listen for free on Spotify or wherever you get your podcasts. Follow us and tap the bell for episode notifications.
[1] The perspective discusses how the suspected Andes virus (ANDV) associated hantavirus cluster on the expedition cruise ship MV Hondius illustrates a critical preparedness gap in managing rare zoonotic infections in mobile, closed, and medically constrained settings.
[2] https://x.com/HHSGov/status/2054247864532943193?s=20 May 12: All 16 Americans who arrived yesterday at the @unmc Regional Emerging Special Pathogen Treatment Center (RESPTC) in Omaha after traveling on the MV Hondius cruise ship currently remain asymptomatic. Last night, the mildly symptomatic U.S. passenger taken to the @EmoryUniversity RESPTC in Atlanta tested negative for the Andes variant of hantavirus.
[3] https://x.com/WHO/status/2054207705452020119?s=20 Update on #hantavirus:
As of 12 May, 12h00 CEST, a total of 11 cases, including 3 deaths, have been reported. Nine of the 11 cases are confirmed, and the other 2 are probable. All are among passengers or crew on the ship.
We expect more cases given the dynamics of spread on a ship and the virus’ incubation period.
At the moment, there is no sign that we are seeing the start of a larger outbreak.
Passengers and crew are being followed up in their countries, where WHO recommends a 42-day quarantine at home or in a facility starting from day of departure from the ship.
WHO Technical Note for the disembarkation & onward management of MV Hondius passengers & crew https://bit.ly/4u1BT5I
[4] CDC: Andes virus can cause hantavirus pulmonary syndrome (HPS), which affects the lungs. HPS can be deadly: 38% of people who develop respiratory symptoms may die from the disease.
[5] WHO: Hantavirus infections are associated with a case fatality rate of <1–15% in Asia and Europe and up to 50% in the Americas
[6] From November 2018 through February 2019, person-to-person transmission of Andes virus (ANDV) hantavirus pulmonary syndrome occurred in Chubut Province, Argentina, and resulted in 34 confirmed infections and 11 deaths
[7] CDC: Andes virus can cause hantavirus pulmonary syndrome (HPS), which affects the lungs. HPS can be deadly: 38% of people who develop respiratory symptoms may die from the disease.
[8] WHO: Hantavirus infections are associated with a case fatality rate of <1–15% in Asia and Europe and up to 50% in the Americas
[9] Transmission to humans occurs by exposure to infected rodents in endemic areas; however, Andes hantavirus is unique in that it can be transmitted from person to person.
[10] From May 7: On April 24, nearly two weeks after the first passenger had died on board, more than two dozen people from at least 12 different countries left the ship without contact tracing, the ship's operator and Dutch officials said Thursday.
[11] Deaths as of May 13, 2026: Case 1 “An adult male developed symptoms of fever, headache, and mild diarrhoea on 6 April 2026 while on board the ship. By 11 April, the case developed respiratory distress and died on board on the same day.”
Case 2 “An adult female, who was a close contact of case 1, went ashore at Saint Helena on 24 April 2026 with gastrointestinal symptoms. She subsequently deteriorated during a flight to Johannesburg, South Africa, on 25 April. She later died upon arrival at the emergency department on 26 April.”
Case 4 “An adult female, with presentation of pneumonia, died on 2 May 2026. The onset of symptoms was on 28 April, with fever and a general feeling of being unwell.”
[12] Harkins received a B.S degree in Biology (1988) from Texas A&M University. She received her MD degree (1992) from Southwestern University. Following her MD degree, she completed her internship in Delaware and then residency in Internal Medicine at the University of Maryland Medical Systems and a 3 year fellowship in Pulmonary/ Critical Care at University of New Mexico.
[13] Hantavirus disease surveillance in the United States began in 1993 during an outbreak of severe respiratory illness in the Four Corners region – the area where Arizona, Colorado, New Mexico, and Utah meet. Hantavirus pulmonary syndrome (HPS) became a nationally notifiable disease in 1995
[14] During the spring of 1993, a mysterious respiratory disease struck the Four Corners region of the southwestern United States. Persons who became ill were generally young and previously healthy before succumbing to an acute febrile illness that began with simple influenza-like symptoms and often culminated in death by pulmonary edema and cardiovascular collapse. With astonishing speed and efficiency, a collaborative team of federal, state, and local healthcare workers, including clinicians, epidemiologists, and laboratory scientists, identified a newly discovered species of hantavirus as the causative agent of the outbreak.
[15] The family Hantaviridae comprises 52 distinct viral species (ICTV 2023 release), including 35 within the Orthohantavirus genus, many of which are important human pathogens.
[16] Hantaviruses belong to the family Hantaviridae, within the order Bunyavirales. Each hantavirus is typically associated with a specific rodent reservoir species, in which the virus causes long‑term infection without apparent illness. Although many hantavirus species have been identified worldwide, only a limited number are known to cause human disease. Hantaviruses present in North, Central and South America are known to cause HCPS. The Andes virus is part of this family and is known to cause limited human-to-human transmission among close and prolonged contacts, primarily in Argentina and Chile. Hantaviruses found in Europe and Asia are known to cause haemorrhagic fever with HFRS. Human-to-human transmission has not been documented in this part of the world.
[17] Sin Nombre virus (SNV), a member of the Hantavirus genus, causes acute viral pneumonia in humans and is thought to persistently infect mice. The deer mouse, Peromyscus maniculatus, has been identified as the primary reservoir host for SNV.
[18] Andes virus is a type of hantavirus spread by rodents in South America and, less commonly, by other infected people. The rodents that carry Andes virus have not been found in the United States. It can cause a severe respiratory disease in people, called Hantavirus Pulmonary Syndrome (HPS).
[19] 2024: Out of 3,382 abstracts reviewed, 110 studies were selected, comprising 81,815 observations and 3207 events. The global seroprevalence was calculated at 2.93% (2.34%-3.67%). In terms of geographical distribution, our analysis encompassed 61 studies from the Americas, where the seroprevalence was estimated at 2.43% (95% CI: 1.71%—3.46%), 33 studies from Europe indicating a seroprevalence of 2.98% (95% CI: 2.19%—4.06%), 10 studies from Asia revealing a seroprevalence of 6.84% (95% CI: 3.64%—12.50%), and 6 studies from Africa demonstrating a seroprevalence of 2.21% (95% CI: 1.82%—2.71%). Subgroup analysis underscored varying seroprevalence rates across different populations, settings, and occupations, highlighting the necessity for targeted interventions and preventive measures….The presence of these viruses across the world, even in areas where clinical cases are rare, suggests that widespread exposure has occurred globally, with many individuals likely coming into contact with the virus without developing severe illness…it is possible that unidentified hantaviruses species or groups circulating in rodent, shrew, bat, and other zoonotic reservoir populations may result in clinically insignificant asymptomatic infections, explaining some of the background seropositivity [144, 145].
[20] e.g., in this one study - examining Northwestern Hantavirus Syndrome in N. Argentina. Between 1997 and 2000, 30 HPS cases were diagnosed in Jujuy Province (population 512,329). Most patients had a mild clinical course, and the death rate (13.3%) was low. We performed a serologic and epidemiologic survey in residents of the area, in conjunction with a serologic study in rodents. The prevalence of hantavirus antibodies in the general human population was 6.5%, one of the highest reported in the literature.
[21] HCPS begins with a febrile prodrome: myalgias, headaches, chills, abdominal pain, vomiting, diarrhoea, arthralgia, conjunctival injection, and retro-ocular pain that lasts 2–7 days
[22] Initial symptoms of infection are very similar and include an abrupt onset of high fever, malaise, myalgia, back and abdominal pain, and other influenza-like symptoms.
[23] However, some patients only develop prodromal phase symptoms and do not progress
to the cardiopulmonary phase.8,49 More than half of SNV [Sin Nombre] and ANDV [Andes Virus] infections are severe, whereas CHOV is associated with a milder form for which less than 10% of patients develop respiratory failure, and shock is rare.26,41,57
[24] Hantaviruses do not cause significant pathological effects, suggesting that immune mechanisms rather than direct viral cytopathology can explain the complex pathogenesis of HFRS and HCPS. Currently, it is assumed to be a multifactoral process and includes T-cell mediated endothelial damage, immune effectors, cytokines and chemokines, as well as a b3-integrin (used by pathogenic hantaviruses as receptors) dysfunction-mediated increase of vascular permeability
[25] Various pathogens, autoimmune and malignant diseases, but also genetic disorders and certain therapeutic interventions, can lead to life-threatening systemic inflammatory syndromes in the human body. Their common feature is a massive release of cytokines due to excessive activation of immune cells. This dysregulated inflammatory response leads to self-reinforcing feedback and may, ultimately, be life-threatening to the host.These conditions are widely referred to as cytokine release syndrome (CRS) or, in particularly severe courses, cytokine storm (CS).
[26] The cytokines that we observed to be upregulated in the serum of HPS cases are involved in a number of antiviral defense mechanisms including proliferation, maturation, and activation of leukocytes, as well as survival of leukocytes, and regulation of endothelial monolayer permeability (Table 2). High levels of IL-1α, IL-6, MIF, and TNF-β suggest a strong proinflammatory milieu in the serum of HPS cases, thus promoting both inflammation and activation of immune responses.
[27] Liver damage in severe acute respiratory coronavirus 2 infection occurs in patients with or without preexisting liver disorders, posing a significant complication and mortality risk. During coronavirus disease 2019 (COVID-19), abnormal liver function is typically observed. However, liver injury may occur because of the treatment as well. Ischemia, cytokine storm, and hypoxia were identified as the three major factors contributing to liver damage during COVID-19.
[28] Hantaviruses predominantly infect the endothelial cell lining of vessels and nonlytically cause two diseases: hemorrhagic fever with renal syndrome (HFRS) and hantavirus pulmonary syndrome (HPS).1–13 The mechanisms by which hantaviruses disrupt fluid barrier integrity and clearance functions of the endothelium are beginning to be disclosed and appear to involve dysregulating EC functions that normally restrict fluid leakage from vessels and clear fluid from tissues.
[29] Endothelial cells of capillaries and small vessels are the principal targets of hantaviruses, and increased vascular permeability is central to pathogenesis. Increased permeability does not appear to be caused by a lytic effect of the virus, but rather by functional changes of the endothelial barrier by mechanisms that remain poorly understood.
[30] Increased permeability of microvascular endothelium seems to be a common effect of hantavirus infection. In the complex pathogenesis of hantavirus infection it is suggested that not the direct viral cytopathology, but immune mechanisms may play an important role
[31] In various human diseases, an increase in capillary permeability to proteins leads to the loss of protein-rich fluid from the intravascular to the interstitial space. Although sepsis is the disease most commonly associated with this phenomenon, many other diseases can lead to a “sepsis-like” syndrome with manifestations of diffuse pitting edema, exudative serous cavity effusions, noncardiogenic pulmonary edema, hypotension, and, in some cases, hypovolemic shock with multiple-organ failure. The term capillary leak syndrome has been used to describe this constellation of disease manifestations associated with an increased capillary permeability to proteins.
[32] Hantavirus cardiopulmonary syndrome is characterized by pulmonary capillary leakage and alveolar flooding, resulting in 50% mortality due to fulminant hypoxic respiratory failure.
[33] Those who develop cardiopulmonary phase manifest a rapid transition ensuing worsening of respiratory symptoms. Cardiopulmonary failure usually develops within 8-24 h of this phase.
[34]Cardiogenic shock is a primary cardiac disorder characterized by a low cardiac output state of circulatory failure that results in end-organ hypoperfusion and tissue hypoxia.
[35] CDC: Andes virus can cause hantavirus pulmonary syndrome (HPS), which affects the lungs. HPS can be deadly: 38% of people who develop respiratory symptoms may die from the disease.
[36] WHO: Hantavirus infections are associated with a case fatality rate of <1–15% in Asia and Europe and up to 50% in the Americas
[37] From November 2018 through February 2019, person-to-person transmission of Andes virus (ANDV) hantavirus pulmonary syndrome occurred in Chubut Province, Argentina, and resulted in 34 confirmed infections and 11 deaths
[38] Although the viruses causing HCPS in North and South America were discovered two decades ago, there is still no FDA approved vaccine or antiviral therapeutic for HCPS.
[39] In extracorporeal membrane oxygenation (ECMO), blood is pumped outside of the body to a heart-lung machine. The machine removes carbon dioxide and sends oxygen-rich blood back to the body.
[40] Veno-venous ECMO is an “artificial lung” that provides oxygenation and removes carbon dioxide. It is used in cases of severe respiratory failure and requires a functional native heart as it does not provide any cardiac support.
[41] Hantaviruses are important zoonotic pathogens of public health importance that are found on all continents except Antarctica and are associated with hemorrhagic fever with renal syndrome (HFRS) in the Old World and hantavirus pulmonary syndrome (HPS) in the New World.
[42]For most of the last 50 years rodents have been considered to be the primary hosts of hantaviruses, with hantavirus evolution thought to reflect a process of virus-rodent co-divergence over a time-scale of millions of years, with occasional spill-over into humans. However, recent discoveries have revealed that hantaviruses infect a more diverse range of mammalian hosts, particularly Chiroptera (bats) and Soricomorpha (moles and shrews)
[43] Neil serves as Executive Director of the Preventing Pandemics at the Source Coalition and Orchestrator in Residence at Integral, where he champions bold, science-driven solutions for people and planet. A former CDC epidemiologist, Neil has led high-stakes outbreak investigations around the world—from Anthrax to Zika.
[44] Transmission mainly occurs via inhalation of aerosolised viral particles shed in rodent urine, faeces, and saliva.
[45] Puumala virus (PUUV) is the predominant endemic hantavirus in Europe. A large proportion of PUUV-infected patients suffer from gastrointestinal symptoms of unclear origin. In this study we demonstrate that PUUV infection can occur via the alimentary tract….PUUV retained infectivity in gastric juice at pH >3.
[46] Moreover, in the Syrian hamster model established for South American Andes virus (ANDV) intragastric inoculation can result in lethal disease, albeit with a higher 50% lethal dose (LD50) than the more effective intramuscular (i.m.), subcutaneous, intranasal (i.n.), and intraperitoneal delivery routes (Hooper et al., 2008). In rare cases, contact to contaminated food was named as a possible risk factor for human hantavirus infections (Ruo et al., 1994). Moreover, smoking was shown to be a risk factor for a PUUV infection in at least two studies (Van Loock et al., 1999; Vapalahti et al., 2010) and a possible ingestion of rodent feces or urine caused by poor hand hygiene was stated in this context (Clement et al., 2011). These findings indicate that the gut is affected in human hantavirus disease and that the infection via the alimentary tract might be a possible route of infection.
[48] Hantavirus infections are relatively uncommon globally but are associated with a case fatality rate of <1–15% in Asia and Europe and up to 50% in the Americas. Worldwide, it is estimated that from 10 000 to over 100 000 infections occur each year (1, 2, 3), with the largest burden in Asia and Europe.
[49] Based on currently available information, the working hypothesis is that case 1 most probably acquired the infection prior to boarding.. Investigations on the travel history and potential exposures of the first case in the Southern Cone subregion of the Americas are ongoing and suggest possible exposure to rodents during bird watching activities.
[50] [English translation from Google] “In a statement released two days ago by the National Ministry of Health, it was revealed that both they and the National Administration of Laboratories and Institutes “Dr. Carlos Malbrán” (ANLIS Malbrán) are not ruling out the presence of potential disease vectors on Tierra del Fuego. Several tourists are visiting the southernmost landfill to observe a carrion bird that feeds there.”
[51] https://www.bbc.com/news/articles/cx21ej471g2o One theory suggests a passenger may have been infected at a landfill site on the outskirts of Ushuaia, where tourists often visit to watch birds and where waste attracts rats and mice. Argentinian officials who spoke anonymously to some news outlets have said that is their leading hypothesis.
[52] To determine the combined global prevalence of Orthohantavirus infection in rodents A total of 35,706 rodents (229 studies) were evaluated for ELISA, in which 3360 were found positive, for seroprevalence of 4.9%
[53] Andes hantavirus is unique in that it can be transmitted from person to person.
[54] Andes virus is unique among hantaviruses because it can be transmitted from person to person. This mechanism was previously supported by epidemiologic data and genetic evidence based only on partial sequences. We used full-length virus sequencing to confirm person-to-person transmission of this virus in a cluster of 3 cases in Argentina in 2014.
[55] People get hantavirus from contact with rodents like rats and mice, especially when exposed to their urine, droppings, and saliva. It can also spread through a bite or scratch by a rodent, but this is rare.
[56] Signs and symptoms of HPS due to Andes virus appear 4 to 42 days after exposure.
[57] ANDV is the unique hantavirus capable of being transmitted from person-to-person (5–7). Infection by this route takes place during the early prodromal phase, and the incubation period ranges from 9 to 40 days (8).
[58] WHO "Contact tracing of passengers who disembarked in St Helena is ongoing; passengers have been contacted and advised to self-monitor for symptoms. Additionally, passengers who travelled on the same flight from St Helena to South Africa with one of the cases who was subsequently confirmed, have been contacted." https://www.who.int/emergencies/disease-outbreak-news/item/2026-DON600
[60] We performed phylogenetic analysis of ANDV/ARG and Buenos Aires virus (BASV) small (S) and medium (M) genomic segments as well as the ANDV/ARG large (L) segment. Coding-complete nucleic-acid sequences determined in this study were assessed together with previously determined sequences of ANDV, ANDV-like viruses Lechiguanas virus (LECV) and Orán virus (ORNV), BASV/BA02-C1S, and several American orthohantaviruses (Laguna Negra virus [LANV], Sin Nombre virus [SNV], Maporal virus [MAPV], Rio Mamoré virus [RIOMV], and Choclo virus [CHOV])....
In the M segment, the amino acid change T641I is also shared among ANDV strains associated with person-to-person-transmission but not among ANDV-like viruses. However, the change is also found in ANDV/NRC-6/18, which has not been associated with person-to-person transmission, and it is absent in ANDV/NRC-3/18, which has been involved in an event of secondary transmission (Table 3). T641 is located in the signal peptide of Gc, in the region preceding the hyperconserved cleavage site WAASA. Because host protease binding sites are guided by the signal from this region (22), we hypothesize that this change might affect the dynamics and speed of ANDV glycoprotein retention and trafficking.
[61] Hantavirus Gn/Gc glycoproteins are the only viral proteins exposed on the surface of virions, which facilitate virus attachment and entry to the cells. … Due to their variability in Gn sequence, distinct hantavirus clades are likely to use different attachment factors and/or receptors
[62] Thus, we performed a systems-level comparison of the Old World Hantaan virus (HTNV) and New World hantaviruses, ANDV and Sin Nombre virus (SNV), using human lung, heart, and brain cell models, alongside lipidomic and transcriptomic profiling. We observed that ANDV exhibits broad tropism, infecting all tested cell types, including lung epithelial cells. HTNV replicated in lung endothelial, heart, and brain cells, whereas SNV replication was largely confined to lung endothelial cells.
[63] we further investigated the hantaviral tropism of lung epithelium using a primary human distal 3D lung organoid model (Fig 2B). Through this model system [54], we observed that ANDV replicated at a higher level compared to HTNV and SNV, which was similar to the responses we noted in Calu-3 cells (Fig 2A).
[64]From November 2018 through February 2019, person-to-person transmission of Andes virus (ANDV) hantavirus pulmonary syndrome occurred in Chubut Province, Argentina, and resulted in 34 confirmed infections and 11 deaths. Understanding the genomic, epidemiologic, and clinical characteristics of person-to-person transmission of ANDV is crucial to designing effective interventions.
[65] The index case had environmental exposure prior to symptom onset on 2 November, and subsequently attended a party on 3 November.
[66] Our findings traced the first person-to-person transmission event to a birthday party with approximately 100 guests. The index patient (Patient 1) attended the event for 90 minutes and was reportedly symptomatic at the time, with fever and malaise. Five persons (Patients 2 through 6) who had been seated close to Patient 1 reported onset of symptoms consistent with ANDV hantavirus pulmonary syndrome between 17 and 24 days after the party (Fig. S3). Patient 2 was the most likely source for six infections in other persons during the early prodromal phase because of his active social life. Patient 2 died 16 days after symptom onset, and his spouse (Patient 9) was febrile while attending his wake. An additional 10 persons who attended the wake and were in close contact with Patient 9 became ill between 14 and 40 days after the wake for Patient 2.
[67] Among patients with ANDV hantavirus pulmonary syndrome, high viral titers in combination with attendance at massive social gatherings or extensive contact among persons were associated with a higher likelihood of transmission…. "Among the first 18 patients with confirmed infection (who had not yet been isolated), those with higher viral loads were more likely to spread infection to another person"
[68] Prospective Evaluation of Household Contacts of Persons with Hantavirus Cardiopulmonary Syndrome in Chile: We enrolled 76 index case patients and 476 household contacts, of whom 16 (3.4%) developed HCPS; 32.6% of 92 cases occurred in household clusters. Person-to-person transmission was definite in 3, probable in 9, and possible in 2 of the 16 additional household case patients. We detected ANDV RNA by RTPCR in peripheral blood cells 5–15 days before the onset of symptoms or the appearance of anti-hantavirus antibodies. …We compared the exposure history for the 16 household contacts (3.4%) who developed HCPS and the 460 (96.6%) who remained uninfected. The risk of HCPS was 17.6% among sex partners of index case patients, versus 1.2% among other household contacts (P < .001)....sleeping in the same bed or room; exposure to saliva ((deep kissing), urine, and semen; and demolition of a shed were all also associated with an increased risk.
[69] we describe the long-term post-infection follow-up of a 55-year-old man….after full recovery from ANDV HCPS. We detected high neutralizing titers in the blood 6 years after the onset of the disease, implying a long-lasting immune response….After separating cells from the seminal plasma, viral RNA was detectable mostly in the cells and, to a lesser extent, in the seminal plasma fraction, indicating the cellular association of the virus.
[70] For measles, R0 is often cited to be 12–18, which means that each person with measles would, on average, infect 12–18 other people in a totally susceptible population.
[71] The median reproductive number (the number of secondary cases caused by an infected person during the infectious period) was 2.12 before the control measures were enforced and decreased to 0.96 after the measures were implemented.
[72] HPS is not characterized by significant cytopathology within the respiratory epithelium or endothelium (68). This pathology contrasts with other respiratory pathogens, such as influenza A virus, which primarily infect epithelial cells, resulting in high levels of cell death and tissue damage (26). In fact, hantavirus pathogenesis is best compared to viruses such as measles virus (32, 50) and Epstein-Barr virus (54) that interact initially but transiently with the respiratory epithelium in order to gain access to other tissues and cell types that are the major sites for viral replication. The initial interactions of hantaviruses within the respiratory tract are poorly understood; however, following inhalation the virus must traverse the respiratory tract to gain access to the pulmonary epithelium and endothelium where disease pathology is localized.
[73] Once exposed to SARS-CoV-2, the amount of virus entering the host tissues depends on the expression level of principal receptors in the airway epithelial cells. The subsequent immune response and inflammatory substances secreted by infected epithelial cells play an essential role in initiating infection and triggering inflammation. Therefore, ACE2 expression and epithelial cell-derived inflammatory markers are associated with the clinical course and prognosis of COVID-19.
[74] https://www.nbcnews.com/health/health-news/hantavirus-cases-rise-11-cruise-ship-passengers-quarantine-rcna344683
[75] https://www.tyla.com/news/hantavirus-cruise-ship-mv-hondius-latest-alicante-case-356426-20260508 Passenger on same plane as woman who died from hantavirus believed to be infected
[76]
https://www.dutchnews.nl/2026/05/possible-hantavirus-case-reported-in-spain-linked-to-klm-flight/?utm_source=chatgpt.com Another possible hantavirus infection has been reported in Spain. A passenger on the KLM flight that was briefly boarded by a Dutch woman who later died after contracting the virus has also developed symptoms, Spain’s health ministry said on Friday.
The woman, from Alicante, was on the flight from Johannesburg to Amsterdam on April 25. She is coughing and reports “general malaise,” and was seated two rows behind the Dutch passenger, junior health minister Javier Padilla told reporters.
The Spanish woman is now being tested for the virus. The World Health Organization confirmed on Friday that a KLM cabin crew member on the same flight, who had been admitted to Amsterdam UMC on Thursday, tested negative.
NBC: Spanish officials said a woman from Alicante who was on the same flight as a passenger who later died of hantavirus is being treated at a hospital for a suspected infection.
The Spanish Health Ministry said in a Friday briefing that a 32-year-old woman was being treated in her home city after the regional Valencian health authority contacted her through a Europe-wide health alert system.
The woman was “sitting two rows behind the person who died from hantavirus, a person who tested positive, having had only brief contact as they were on board the plane for a short time,” Secretary of State for Health Javier Padilla told a news conference.
On Saturday the woman’s PCR test came back negative for hantavirus, Spanish Minister of Health Mónica Garcia said. A second diagnostic test will be carried out after 24 hours, she said.
[77] https://www.democrata.es/en/current-events/the-woman-admitted-in-alicante-tests-negative-in-a-third-pcr-for-hantavirus/ The third PCR test performed on the woman admitted in Alicante within the hantavirus surveillance protocol has yielded a negative result, according to health sources. [this is the woman who had briefly been on the flight: https://alicantetoday.com/alicante-woman-tests-negative-for-hantavirus-after-cruise-ship-scare_1000268658-a.html ]
[78] We conducted an extensive survey of SNV genetic prevalence in wild-caught small mammal communities throughout New Mexico and observed that 27% of all animals were positive for SNV. Through longitudinal trapping at a site of patient exposure, we found that SNV circulates at a high rate in multiple species over time…. We found that 415 (26%) of the 1,561 tissue samples were positive for SNV viral RNA by qPCR (Table 1 and Fig 1A).
[79] Population estimates for New Mexico (2024)
[81] New Mexico: 129 cases 1993-2023
[82] On the basis of evidence from five reconstructed person-to-person transmission events, the route of infection in secondary cases was possibly through inhalation of droplets or aerosolized virions (Table 1 and Table S7). The time of symptom onset is also critical. In 17 of the 33 (52%) secondary transmission events, transmission from an infected person to a contact who later became infected could be accurately established as the day of onset of fever in the primary case, and the first day of fever was the only time during which there was an interaction between these patients (Table 1).
[83] A fatal case of serologically confirmed hantavirus pulmonary syndrome (HPS) was recently reported in southwestern Argentina. Nucleotide sequence analysis of PCR fragments from conserved regions of the S and M genomic segments of the virus, amplified from RNA extracted from autopsy lung and liver tissues, showed the virus (referred as Andes virus) to be novel.
[84] On August 3, 1996, the song “Macarena" hits no. 1 on the American pop charts. It would spend more time on the Billboard Hot 100 (60 weeks) than any other song in history.
[85] The phylogenetic analysis confirmed that the outbreak was caused by a single spillover event (Figure 1A). The Epuyén/18–19 sequences are most closely related to those recovered from an unrelated case of ANDV hantavirus pulmonary syndrome that occurred in 2018 (the NRC-6/18 strain) in a patient from a neighboring town and to the Epilink/96 strain….Although the Epuyén/18–19 and Epilink/96 sequences were sampled 22 years apart, few genomic mutations were identified among the strains involved in the outbreak that were transmitted from person to person. In addition to their capabilities for sustaining person-to-person transmission, the genomic similarity of the Epuyén/18–19 and Epilink/96 strains suggests that they share the baseline genetic traits for successful cross-species transmission (facilitating spillover into humans) and transmission within a species (facilitating person-to-person transmission) without a need for adaptation to improve viral fitness,