Rochester expert answers Hantavirus questions: Adam Interviews

追加: 2026-05-13

[00:00:11]Hi everybody. Thank you so much for joining us for another episode of Adam Interviews where we are talking to folks in our community who are doing things of note. And today we are joined by Dr. Angela Branch. She is with U Rochester Medicine, an infectious disease specialist. Dr. Branch, thank you so much for joining us. Appreciate it.

[00:00:29]Thank you for having me.

[00:00:30]>> So, the reason we're talking with Dr. Branch right now is because what's happening on the open seas, the cruise ship that took off from Argentina. They have, is it haunt or havirus? I always >> Han virus.

[00:00:41]>> Hont virus. Um, they have a havirus outbreak there. Three people have died.

[00:00:46]Uh, several others have been sickened.

[00:00:47]Around 150 people on board. And now there's discussion of where to bring it.

[00:00:50]Maybe the Canary Islands. It's it's a mess and it's getting international headlines. And I think it's one of those viruses, uh, Dr. branch that people might have heard the name but they don't know much about. So before we get into what's happening right now, this current situation, why don't we just go over what the h virus is?

[00:01:06]>> Yeah. Uh so it's exactly um what it says. It is a viral infection. Um it's uh sort of an unusual virus, one that we don't see very often. Um there are lots of different strains of them. They're mostly um in this part of the world, you know, sort of North America, South America is where we see most um of the haunt viruses uh show up. Um there are 12 of them that have been associated with human diseases. Um and their natural reservoir, sort of who carries them um and brings them into human populations are actually rodents. Um and so it's something that we've seen here in the United States. there's been outbreaks in sort of like the Southwest and sometimes the Northwest. Uh you know, if you're an ID doctor and you're studying um then one of your board questions is usually about one of those outbreaks in the in the four corners of the United States. Um and when it does cause illness, it's usually because someone has come into contact with um secretions or feces or urine from a rodent. Um, and it has to be a pretty major exposure in order to become infected and then it can cause quite severe disease and be quite life by lifethreatening.

[00:02:19]>> And correct me if I'm wrong, it'd almost be you have to inhale. I mean, it would not to get gross, but you'd kind of have to inhale the feces. Correct.

[00:02:26]>> Yeah. You know, because we see it so infrequently. Um, we don't know as much about transmission as we would like to know. Um, it is the virus itself is in these secretions. And so, um, theoretically, we've always believed that you inhale the virus from sort of shifting dust where there's feces and and the virus sort of aerosolizes and then you inhale it into your lungs. Um, which is the the primary sight of infection. Um, and that's what causes disease. Yeah.

[00:02:53]>> Yeah. And then why don't we talk about real briefly, not even real briefly, you can go into as much detail as you want because we have time, but what are the symptoms uh generally? I know there's different versions and all that, but why don't we talk in generality right now?

[00:03:05]So, it's it's interesting. Um, you probably won't even know you're infected for a couple of weeks because the incubation period is a is a median of about 14 days. And so, 14 days after you've been in a cabin someplace where there's a lot of mice droppings um and you might have inhaled the viruses, then you'll you might develop sort of a non-specific illness. It looks a lot like the flu. Uh you'll feel feverish, chilly, you'll have lots of muscle aches. Um you can have some nausea, some uh abdominal pain. and that sort of thing. Um, and that's uh something that'll last for anywhere from a few days to a week. It's what we call a prod. Um, it's non-specific and we don't know, you won't know what it is until it continues to progress. But most viral illnesses will resolve in about a week's time um in healthy people at least. And so after that week is when you really start to see the more severe symptoms.

[00:03:59]Um and usually it's respiratory symptoms because from this point it's moved to just not just being uh your body's systemic response to having an infection which is what that prodrome is. Um now it becomes pneumonia what we call the cardopulmonary phase. Uh so you'll get a dry cough. Um you'll become really short of breath. Um and because of the inflammation is now sort of really focused on the lungs. Um the lungs become filled up with a lot of fluid very quickly. Um and people usually present to the hospital uh in the early stages of this cardopulmonary phase. Um and then that rapidly can progress to uh respiratory failure, needing to be on a ventilator um and even shock. Uh what's happening at this point is that you have a very severe pneumonia. Um but it's not just the viral pneumonia. It's what your body is doing to sort of respond to that ammonia that this sort of systemwide inflammation um that's concentrated very much in the lungs but is also um producing sort of systemwide inflammation and that systemwide inflammation means that everything gets filled with fluid. Your lungs get filled with fluid. Uh your blood vessels become very leaky. Um some of your cells don't work as well. You know, your clotting cells, your blood cells, those sorts of things. Um and so we start to see sort of a systemwide inflam inflammatory process happening. Uh that that that's the real life-threatening part of the illness. Um when patients get that sick, they're often in the hospital. They're in the ICU most of the time. Uh many of them are on the ventilator. Um and so they do require quite a lot of supportive care.

[00:05:36]>> And do all patients who go without treatment jump into that second phase eventually?

[00:05:43]um not all but a lot of them do. Um I would say easily half, maybe more. Um again, it's not something we see that often. So we don't have the epidemiology data that we have for say something like flu where we get an epidemic every year.

[00:05:58]Um if we see, you know, 50 cases in the United States in a year, that's a lot.

[00:06:03]Um, and so without that those numbers, you know, it's hard to to give an exact number of of of who sort of ends up in this really severe case, but I would say um, at least half of cases end up there.

[00:06:15]Um, maybe even more. Certainly, every time we see this case and we make a diagnosis, they're in that phase. We rarely see HTO virus that sort of ends at the prodrome uh, because they never get sick enough to end up in the hospital. So when when they do present to their doctors um they're usually quite severely ill.

[00:06:34]>> That's interesting. And I was reading that the fatality the mortality rate fatality rate of this 1 to 5% it might not seem like a lot but I've read enough about diseases that's pretty high.

[00:06:46]>> Yeah it is really high. Um, I mean that's for a virus in particular. Um, and the fact that it, you know, you don't have to be someone who is, um, frail or have a lot of medical conditions for for that to be true. Um, it's one of the few viruses where sort of anyone could be at risk to to have a very severe outcome.

[00:07:05]>> Yeah. And then on top of that, and this is where I really want to, you know, lean on your expertise here, is they're saying that I believe it was a South African authorities confirmed that the type of hunter virus, you said there's like 12 of them. This type of strain is the Andes strain, which has been documented to be able to travel from human to human, which is unlike a lot of the other strains. I'd love to get your take on that.

[00:07:29]Um, you know, I again I would say that there's still the jury is still a little bit out on that. Um, one of the problems with this is, um, when you're looking at clusters of infection, um, for example, within a household or a family, um, most likely all those people will have been exposed to the same thing. Um, so it's very difficult to know if they really transmitted it to each other or they were just all exposed to the same um sort of scenario or scene that allowed one person to contract haunt virus and they all did. Um but I think um some of the studies where we look at the the genetic material of the virus has suggested that of all the strains that's probably the only one um that we think could have persontoperson um transmission. And even with that it's not entirely clear how that persontoerson transmission occurs. Um it's not for example going to be the same way you get it from rodent feces.

[00:08:34]So you're not coughing something in the air that somebody then aerosolizes. Um it's probably to like related to some heavy um inoculation from secretions like for example sexual contact um or getting um you know exposed to a lot of blood or a lot of saliva or something like that. Uh so I if it if it does occur um and again we don't have a lot of data on this then it's really only been reported with that one strain um and the the exact mode that it goes from person to person is still something we don't have a clear understanding of.

[00:09:11]>> So what is the threat to I think a lot of people we've all lived through the pandemic now and we thought the possible was impossible and we you know it started in China and then Italy and I think a lot of us kind of thought it will never end up here. Is there a threat to us here in the US from what's happening on this one particular cruise ship?

[00:09:30]>> Well, h virus is always a a threat to us. Um I think uh who's the last person that died in the United States? Gene Hackman, right? He and his wife were thought to have had hirus last summer was it I think it was >> and they both died from that. And so we see cases every year in the United States. It's always a potential threat.

[00:09:50]Um I think what makes this this unique um is the cluster of cases that occurred on a cruise ship. Um and so there there's questions that you that you know infectious disease epidemiologists and folks like the CDC and who are going to be asking themselves. They're going to be asking how did these people get infected in the first place? Remember that 14day incubation period. So it doesn't necessarily mean they contracted it on the ship. It could mean that they got it, you know, wherever they came from. Um, but then you have seven cases and so are all seven of those cases in the same family because if it's not in the same family then now you have a potential transmission event that did occur on the ship itself. And so the question will be did that transmission event on the ship occur because there are mice on the ship and there's mice droppings and there's actually an exposure that happened on the ship to the natural reservoir or was it in fact one or two people who were infected and then they subsequently infected the other five and so these are I think the questions and the investigations that are going to be needed. Um, and then if that is the case, then you know a c I've been on cruises. I'm sure you have too.

[00:10:59]C cruise ships are very um intensely um you know enclosed spaces like it's it's a it's an enclosed environment. Um and so you come into contact with dozens of people and the same dozens of people um you know half a dozen time a day. So there's lots of potential for exposures.

[00:11:20]There's pools, you know, there's um urine that's, you know, sort of sort of not as, you know, when in mass pools, there's always a urine situation.

[00:11:30]There's there's food, there's exchange of food and drinks and all these different things happening. People on vacation, they're just, you know, doing what you do when you're on vacation, which is loosen a little bit some of your heightened awareness of your environment and and what's safe and what's not safe. foam and so I think um there's a lot of potential risk for um exposures of secretions which if if this is in fact a case of persontoperson transmission with this um extremely rare version of hivirus um then I think everybody on that ship potentially could be at risk and um and then you you sort of have to to keep them out to sea long enough to make sure that they don't become a risk to the folks that um they live with in their communities back home. Uh, so, you know, I think there's probably a lot of investigation going on. I'm not close enough to it to know exactly what's happening. Although, maybe I should call someone at the CDC and find out that I know what's going on. Um, but I think um those those questions are are really what they need to what they'll what will drive uh the potential risk to the rest of us. um who how it happened, you know, whether it was um an infection that occurred in South America somewhere and someone got on the ship already infected and not knowing that they were um and if all those cases are clustered within a family or or group that might have had the same outside exposure. Um and then again if the possibility of transmission between two unrelated clusters of people um occurred um and if that unrelated transmission is due to um the ship's environment or actually do the persontoperson transmission. I think once we have the answers to those questions then we'll we'll we'll really understand the potential risk.

[00:13:17]>> Yeah. No. So, so what I'm hearing is obviously, and I'm glad you you pointed it out, uh, anybody, you know, we are we are all at risk of Honda virus because we could come in um into contact with uh, you know, rodent populations in all sorts of places. Um, and >> by the way, we have it in here in upstate New York, too, which people don't even don't even fully recognize.

[00:13:36]We have our own version of of Hunter virus that's actually called the New York version.

[00:13:41]>> Really? What's that one like? Um it's a little similar to the one that's out west, the sin synomere uh one. Um and you know can cause cardiopulmonary syndromes similar to to all the others.

[00:13:54]>> That's interesting. Okay. Well, that's good to know. So So what you're saying is you know and rightly so when I asked you know what's the risk and you said well it's there for everyone in our area because it's it's in our population. I guess um to rework that question a little bit. What's the threat from the folks on that ship right now to us? I mean, given what you're saying is it's it's more difficult to spread this than say a flu or a common cold. So, I I'm wondering if while we are at risk because it's here, are we at risk because of those folks on the ship right now?

[00:14:26]>> I think if those folks on the ship all some of them are are all of them potentially contracted it on the ship and again those folks did in fact transmit it to each other.

[00:14:40]um meaning that they are unrelated to each other. Um and therefore it wasn't because they lived in the same household or or something like that and got infected together elsewhere, but they really did contract it on the ship and there's no clear chain of transmission.

[00:14:57]Um then I think that highly raises the possibility um and maybe even establishes the possibility of persontoperson transmission. Um so then what you have to do is quarantine that chip until um everyone who is infected recovers. Um and that's usually about 3 weeks or so from the onset of of symptoms um is when they might begin to recover. And then you also need at least two weeks for every other person exposed um to get past that incubation period and make sure that they don't develop symptoms. So I would say um you know whoever is managing that would probably establish a quarantine for something along the lines of three to four weeks.

[00:15:43]Um and then assuming that you have no further cases and no further outbreaks, then it really isn't a threat to to us that part specific outbreak on that specific ship. Um, but if that's not if anything less than two weeks and and probably less than three weeks um isn't pursued, then I think there there could be a potential um transmission um that occurs once people are able to leave the ship.

[00:16:11]>> That's uh very interesting. And um when we talked about co we obviously learned about the ability of viruses to mutate where I think we had the delta version that was more infectious. Is that the same thing with the haunt virus? I mean, can these strains kind of mutate into their own individual things and and become harder or easier to um ward off or um get infected with?

[00:16:35]>> No. Um well, I I won't say no because it is an RNA virus. Single strand negative sense RNA virus and COVID are and influenza, those are all RNA viruses.

[00:16:47]RNA viruses do mutate very quickly. Um I doubt this um would mutate to the point where um it somehow uh becomes more infectious. Um I think it's you know there's no pressure uh for it to do that at this point and only seven cases um and it being sort of a difficult uh virus to become infected with in the first place. you need quite a lot of it to become infected. Um and a significant exposure unlike CO where um you know in one droplet of um of of secretions that you cough into the air there's probably um dozens of viral particles that you can become infected with. Um so this is this isn't quite the same as that. Um, and so I don't I don't I don't expect to see um a lot of mutations within hosts that then uh some somehow changes the fitness or the infectiousness of the virus.

[00:17:41]>> Yeah, it's interesting uh Dr. Branch because I was talking with an expert about Lyme disease last week or the week before and we were talking about a vaccine and I had no idea. He informed me that we actually did have a vaccine uh two or three decades ago for Lyme disease, but it was so rare at that point that apparently it wasn't financially viable or just not enough people were using it because that wasn't that much of a threat. Now we have two clinical trials for the disease because it is so prevalent out there. So I'm I'm guessing because I haven't heard about it. There's no vaccine I'm guessing for the haunt virus and I'm wondering if that's true if that's because there just aren't that many cases to justify that kind of research.

[00:18:19]Um there is no vaccine. Um we don't have a lot of cases of hund viruses. So that might be partly why uh we you know the vaccine research and development for this particular um infection has not been as robust as some other spaces. Um yeah I yeah that's probably one of the main main reasons. I mean we we uh develop vaccines when it's a real threat to human populations. and this one sort of is, but it's not that frequent a threat. Uh, so yeah, >> it's going to be interesting that investigation that you were talking about because uh the Andes strain, I think, is primarily in Chile and Argentina and that's where the ship took off. So, you know, you start to see the correlation there and trying to figure out um where things are and then you see the fear of apparently the government on the Canary Islands is telling Spain, don't come here even though Spain wants to send them there. Yeah, this becomes a very tricky situation as we've learned.

[00:19:18]Again, I keep hearkening back to the pandemic, but so much about this is perception and and not controlling because that's not the right word, but um informing the public to make sure that there's the messaging is right about what what exactly is happening out there. And I'd love to get your take having kind of lived through the pandemic and seeing a situation like this. What are your initial thoughts on handling this and getting information out?

[00:19:43]Um, I think I think I guess I'm always surprised um at what becomes something that people want to know more about and don't. Um, h virus again isn't new the way SARS KV2 and the co pandemic was in fact a new virus. Um, it did cause a worldwide pandemic. Um, I think that the threat of honto virus as a a potential infection has has always been um something that that's been true um for people who like to spend a lot of time outdoors, do a lot of hiking, um spend time in cabins and so forth, wooded areas um where you might have rodents. Um it's I think it's always been a potential threat. If you if you visit um certain parts of the world like South America, even if you visit certain parts of our country, um the the risk is higher than in other parts. Um, so I I don't really put this in the same um sort of perspective as I as I do SARS um as I did as I do yearly influenza epidemics um or certain other things where the attack rate is very high and we know it's going to be very high. Um as I said with haunt virus it's sort of like plague um it's there when you get it you can get really sick. um you should take really good precautions and not certainly not to avoid these spaces like don't not go to um Washington or Oregon or or Arizona or New Mexico and and and you know camp in the desert if that's what you want to do. Um those are wonderful um and beautiful experiences that people should engage in. But um people should always be sort of aware of some of the the risks that exist in our environment. Um and that um you know you should take precautions. It's sort of like what I tell people when they go hiking around here. When you get back home you should be checking and make sure you don't have ticks. Like 30% of our ticks have lime are infected with with lime. Um and so it's it's very very prevalent in New York State. And yet, how many people actually when they come home from hiking, um, even in, you know, Highland Park do a full head to toe chick tick check? I I don't do it all the time, and I know I should, um, and I'm sure lots of people don't, but these are the things that I think we should be messaging, um, to folks in our community, um, to folks in our country, um, and how sort of CDC and WHO and physicians and healthc care providers and and certainly news providers should be messaging these things. there are risks out there. Hont virus is one of them. Um and you know like know what the risks are. Know what the potential um symptoms could be and uh do what you can to enjoy the things that you're going to do um in a way that is safe.

[00:22:41]>> Yeah, I couldn't agree more and I agree so much that I'm going to encourage people watching this to go a few Adam interviews episodes back to our Lyme disease uh show because a lot of great information there um about prevention in particular. And then detection. Um, speaking of detection, I was wondering and then, uh, we'll we'll wrap up here in a second. I so appreciate your time.

[00:23:01]When someone comes in, as you were noting, um, often the first version of it looks like flu and then even respiratory. What this is a two-parter.

[00:23:10]What signals to you that you might be dealing with H virus? And how do you then test for it? Because my concern, I'm sure yours is too, is that you, it's so rare that you don't really think of that right away. Mhm.

[00:23:23]>> Yeah. Well, I'm ID, so I always think about hunt virus.

[00:23:27]>> Okay, that's good. That's good.

[00:23:29]>> You know, it's just one of the things I like to think about. Um, and not and never ever forget because I would never want to miss a case of Honda virus. Um, interestingly enough, there there's no treatment, so there's not like a whole lot you can do about it even find it.

[00:23:42]Um, it's mostly supportive. Uh, but it does help you to understand what's going on with the patient. Help you to understand um what the the natural course of the progression of their illness might look like so you don't freak out when they get worse before they get better. Um, and then it also helps you not to do a lot of other things like give them tons of antibiotics that could end up hurting them. Um, so there's good reasons to test and the only way to make a diagnosis is by actually finding antibodies to the haunt virus in their blood. Uh, so that's usually how we diagnose haunt virus. Um, I usually, you know, I've never diagnosed a case. Well, that's not true. I had one maybe when I was a fellow about a decade or so ago.

[00:24:23]Um, but I certainly haven't I, you know, certainly don't see it very often around here. Um, I think the only reason I thought about it is because the person was so sick. Um, and they had this severe sort of respiratory distress syndrome. Um, where they, you know, their lungs will fill up with fluid and they were in the ICU on a ventilator and on ECMO and you're like, "This is not flu. This is not run-of-the-mill pneumonia." Like, you know, it's something um that causes sort of this severe systemwide inflammation. This was long before COVID, so that wasn't even on our, you know, on our radar, those kinds of things. Um, and so, um, and then after that, they went into the second phase, which is, uh, what they call the diuretic phase where they just, um, their kidneys shut down for a little bit and then they start to just make lots and lots of urine. They're just pouring water out of themselves. Um, and so, um, when we saw that particular sort of progression, um, then it was like, oh, this could be Honda virus. let's check some antibodies. Um so now when I see someone who comes in with really unclear unexplained severe um respiratory distress syndrome um then I then Honda virus is always in my differential um as a first thought and then I go and I talk to them and their family and I'm like have you been to the southwest? Have you been to Oregon? Because that's usually where cases come from. Um, we rarely see true hauntivirus cardiopulmonary syndrome from people just living upstate here in New York. I've never seen a case. I've never even heard of a case. Um, and so depending on their exposures, if they tell me they were out in um, you know, some cabin that was dusty with mouse droppings two weeks ago, then that also kind of heightens my concern and awareness for haunts. I'm like, okay, this isn't my differential. Let's at least check.

[00:26:14]>> Yeah, absolutely. By the way, the lighting looks great despite the uh, light on the background. No, you look great. It actually in a way it even looks more artistic. So, um, a last question for you then. You you kind of mentioned it. Once you start to sniff out what's happening here, you said you test the antibodies. What what do you what does that mean?

[00:26:33]>> Yeah. So, what I'm looking for is an immune response to the virus itself. And usually within a week or so of you getting infected, you'll start to make antibodies to the to the haunt virus.

[00:26:44]Um, two different kinds of antibodies.

[00:26:46]and looking at the the rate and because no otherwise you don't you shouldn't have those antibodies. Um and so if you find them it's usually diagnostic.

[00:26:54]>> Yeah. Very good. Uh Dr. Branch I can't thank you enough for your time. Um just uh so appreciate the information and as you noted you know there there are certain things that I guess creep into the national eye, the public eye and you wonder like huh that's interesting but the confusion is real and uh the answers that you gave are real. So I I greatly appreciate your expertise.

[00:27:16]Okay, thank you. And sorry for the background noise and the lighting.

[00:27:20]>> Oh, no. Are you kid I didn't even notice. There you go. Oh, there goes the lighting again. Uh, no, it looked great and uh I appreciate that. So, Dr. Angela Branch uh talking to us from you Rochester Medicine. Um, obviously uh a wonderful a fountain of information when it comes to haunt virus. Uh, learned a lot. I hope you did too. Please tell your friends and family about the Rochester First app because we are getting some of these incredible people in our area to talk about things they know. With that, take care everyone and we will talk soon. Take care. Okay.

[00:27:49]>> Thank you.