Episode 165: Frustrating Times: H5N1, Mpox, & Vectorborne Disease

Chris Dall: Hello and welcome to the Osterholm Update, a podcast on COVID-19 and other infectious diseases with Dr. Michael Osterholm. Dr. Osterholm is an internationally recognized medical detective and director of the center for Infectious Disease Research and Policy, or CIDRAP, at the University of Minnesota. In this podcast, Doctor Osterholm draws on nearly 50 years of experience investigating infectious disease outbreaks to provide straight talk on the latest infectious disease and public health threats. I'm Chris Dall, reporter for CIDRAP news, and I'm your host for these conversations. Welcome back, everyone, to another episode of The Osterholm Update podcast. School is back in session across the country, and with that comes the likelihood that COVID-19 cases may rise again, following the pattern that we've seen established over the past few years. And that will bring an added level of stress for parents who, according to a new report from U.S. Surgeon General Vivek Murthy, are already facing new stressors that previous generations didn't have to consider, like managing social media and its impact on youth mental health. The work of parenting is essential not only for the health of children but also for the health of society, murthy writes in a foreword to the new report. The stresses parents and caregivers have today are being passed to children in direct and indirect ways, impacting families and communities across America. On this September 5th episode of the podcast, we're going to talk a little bit about that report. Before we dive into what we know you're most interested in what's going on with COVID. We'll also bring you updates on the H5N1 avian flu outbreak in U.S. dairy cattle, and the latest developments in the Mpox outbreak. Explain what's going on with the Eastern equine encephalitis and other mosquito borne viruses you've been hearing about, and answer an ID query on the updated COVID vaccines, and we'll bring you the latest installment of This week in Public health history. But before we get started, we'll begin with Doctor Osterholm's opening comments and dedication.

Dr. Osterholm: Thanks, Chris, and welcome back to all of the podcast family. We're so glad you could join us again. And for those who might be joining us for the first time, I hope that we're able to provide you with the kind of information you're looking for. Uh, needless to say, we cover a wide range of different topic areas. And as Chris introduced today with the podcast here, the topic here is regarding the science are substantial, but we also have a few other goodies we're going to throw in. Let me begin with the obvious Labor Day is now in the rear view mirror. It is the official end of summer, and any of you who have been following this podcast over the years know how much I like light. And so I must admit, getting up early in the morning right now when it's still dark concerns me. Knowing that it's going to be like that for a number of months ahead, but nonetheless, it is the end of summer. There are a lot of other things that begin to happen that are also exciting and, frankly, really interesting. While some of us can cling to the remaining warm weather and pretend it's summer for a while longer, if you are a parent or caregiver for school aged kids, you probably don't share that luxury. Oh, how I remember that so well with my own kids and the excitement of starting school, the start of the school year is an all hands on deck effort for most families. From shopping for school supplies, meeting new teachers, signing up for activities, and carefully choreographing school pickup and drop off routines, this is a busy time of year for some kids.

Dr. Osterholm: It wasn't necessarily a positive time of the year. They didn't have the kinds of resources that could get them new backpacks or new clothes, or for that matter today, computers, iPhones, etc. these are some of the concerning aspects of that school environment. But for all the enthusiasm and opportunity generally that a new school year brings, there's no pretending that it's easy for caregivers. I know that managing a family's needs, balancing work, and supporting your children's education can be stressful, expensive, and overwhelming. It's easy to get caught up in the daily grind. In a well-timed report the Chris just mentioned, the Surgeon General released an advisory highlighting the current state of parental stress and linking parents mental health to the well-being of their children. The report cites national data from 2023 that found that 41% of the parents say that most days they are so stressed they cannot function adequately. Parental stressors include economic instability. Time demands, the safety and health of their children, social media, and their own loneliness and isolation. The advisory underscores that when parents and caregivers take care of their own mental health, they are not just improving their own lives, they're positively impacting their children's lives as well. So as this new school year. Ramps up, I just want to emphasize that self-care is not a luxury. It's a necessity. Prioritize those moments of rest. Seek out support and when needed. Remember, taking care of yourself is an essential part of taking care of your family. And for those of you that aren't parents or in some cases, grandparents, or you don't deal with this type of stress in your day to day lives, consider how you can support your friends, family members, and colleagues who do stress.

Dr. Osterholm: Parents need much more than platitudes. They need more people on their team. So to all parents and caregivers out there, thank you for everything you do. Your love, dedication, and resilience don't go unnoticed. So here it is dedicating this podcast to a new school year filled with growth, learning and the strength to keep thriving together. Now, I just mentioned on several occasions in the dedication here about light. Yep, we're experiencing the ever increasing days. We're almost at that maximum reduction in light of the Northern hemisphere. Today in Minneapolis, sunrise is at 6:40 a.m., sunset at 7:41 p.m. that's 13 hours and 58 seconds of sunlight. We're losing sunlight at about three minutes and two seconds a day. That will creep up a little bit higher through September 21st. And while the sunlight will continue to drop in its length between now and December 20th 21st, the rate at which it drops will slow down. On the other hand, our dear friends and colleagues at the Occidental Belgian Beer House in Vulcan Lane in Auckland, New Zealand, you today have had sunrise at 636. Sunset at 603. That's 11 hours, 27 minutes and 47 seconds. Yeah, we've still got you beat for a little while, but as we're losing sunlight, you're gaining it today. You gain two minutes and 15 seconds, and that number will continue to increase substantially through the end of the month. So enjoy the light, everybody in, particularly when it's the warm days in the fall with a cool breeze, but yet warm enough to remind us that the sun is very important.

Chris Dall: Mike, we've been following the increase in COVID-19 infections here in the United States over the past two months. Are we starting to see any drop off yet, and could that be negated as students across the country head back to school?

Dr. Osterholm: Well, Chris, this summer 2024 wave looks like it may become the summer into the fall 2024 wave, confirming that this virus is not seasonal in any way other than the fact that it occurs in every season. I was actually very pleased to see the CDC finally acknowledge that COVID-19 is not seasonal like influenza, but that it can happen in any season based on the combination of emerging variants and waning immunity. We're in a really interesting time where people are viewing this as much more of a common cold type of virus, and they aren't testing in some cases because they can't access tests, but in many cases because they're choosing not to. But as we've talked about with H5n1, remember, the absence of evidence is not evidence of absence. The virus is out there and it doesn't seem to be going away any time soon. If we look at the wastewater data, it continues to show levels that are considered very high and are unfortunately still increasing in all regions except the West, with wastewater concentrations being a leading indicator of warning us as to what is to come. I'd expect we'll continue to see increasing activity for at least a couple more weeks, if not longer. Looking at state level data, 47 states and the District of Columbia have either high or very high levels. Note this is up from only 43, as opposed to the 47 states in our last episode.

Dr. Osterholm: 16 states and the District of Columbia are high and 31 states, including Minnesota, are very high. Michigan is the only state with low levels, while Arizona and North Dakota didn't have enough data for classification. Again, the absence of evidence here is not evidence of absence. Based on the data from the mere one third of US hospitals that still report their COVID numbers, which will change in November, when hospitals again will be required to report their COVID hospitalizations as they were at the beginning of the pandemic. There are just over 5350 Americans reported to be hospitalized with COVID. This is down from 5430 and around 12% of those hospitalized in the ICU. This is a slight decrease in hospitalizations from the previous week, which could be a positive sign. I've gotten a lot of questions about how these numbers compare to previous peaks, and considering that the 5000 hospitalizations only account for about a third of patients in hospitals in this country, I think the best way for us to make comparisons as to assume that as long as nothing categorically is different happening at the other two thirds of the hospitals in the country, we're probably sitting somewhere in the 14,000 to 16,000 range for hospitalizations at the moment. Again, it'll be very helpful to see the actual numbers come in November 1st when hospitals again have to report these cases. But for now, we have a base and that's it. And we're making estimates on the other two thirds of the hospitals.

Dr. Osterholm: But again, asking the question what are these hospitalizations mean relative to the previous months and years spent with this pandemic? Well, if we look back at the other peaks and use the number of 14 to 16,000 hospitalizations, you can see that actually we still are in pretty darn good shape. If you look back in July of 2020, we hit about 50,000 hospitalizations per week. In January of 2021, we hit 130,000. And in September of 2021, we hit 98,000. We hit our all time peak in January of 2022, with 155,000 hospitalizations in a week. July 2022, we had 40,000. January 20th 2340 4000. September 2023 17,000. And finally, even just at the beginning of this year, January of 2024, we were at 30,000. So again, compare that to even the high estimate of 14 to 16,000. You can see that in fact, we're looking better than we have, even with other increased activity times through the pandemic. Now, I don't usually focus on emergency department numbers, but there have been some interesting trends I want to draw your attention to over the past couple of months, as we've seen COVID-19 activity increase, we are also seeing emergency room visits with diagnosed COVID-19 increase. However, what has stood out to me is the age breakdown of these COVID-19 Ed visits. On July 28th of the summer, the 0 to 11 year olds and the 75 plus age groups both saw 3.55% of their emergency department visits being positive for COVID.

Dr. Osterholm: In other words, 3.5% of Ed patient visits in both these age categories had or were diagnosed with COVID-19. Although this could include some incidental findings of COVID, we suspect that many of these individuals presented to the Ed primarily because of their COVID-19 symptoms. While this seems like a low percentage, that is not why this is interesting. Since July 28th, for the first time since the beginning of the pandemic, the 0 to 11 age group has remained at a higher percentage of ED visits for COVID than the 75 plus age category. Last week, nearly 5% of those 0 to 11 year olds who went to the emergency department either went because of COVID or tested positive for COVID while they were there. This is the highest percentage of this age group has seen throughout the entire pandemic. I bring this up because it really begs the question of who we categorize as high risk. And with these numbers, I think we need to be looking at young kids as a potential at least risk group for vaccination and prioritizing protecting them. I've heard it said many times children very rarely get serious cases of COVID. Well, so far this year, just in calendar 2024, 52 kids 14 years of age and younger have died from COVID. More than half of these individuals had no recognized risk factor for being at increased risk of COVID.

Dr. Osterholm: So it still is a challenge. It is a problem. And I think with the school opening right now, it's going to be quite interesting to see what happens with case numbers within this age group. So stay tuned on this one. But if it were me, and I'll talk more about this in a moment. I'd want to make sure my kids had one dose of vaccine before getting into school. Now, looking at deaths and as we've talked about, they're a lagging indicator. They are unfortunately increasing. Last week was the third straight week with more than a thousand deaths, with a 1262 Americans losing their lives to COVID, or about 180 each day. This also marks the 233rd week, with more than 400 deaths and the eighth straight week with more than 500 deaths. But to put these into context, if we look at previous deaths in the pandemic, we can see that we're actually in a much, much better place than we have been throughout the most recent four years. For example, in April of 2020, one of the first big peaks, we had 17,000 deaths in one week. In July, August of 2020, we had 8000. In January of 2021, 25,000. In September of 2021, 15,000 in January of 2022 21,000. August of 2022 3400. And in September of 2023, we had 1400 deaths a week. So we can see from here is that the number of deaths are surely much lower than we've seen previously in the pandemic.

Dr. Osterholm: I would suggest, however, with over a thousand new deaths a week, that still is a very significant issue. Now, where is this focus of risk in terms of severe illness? As we've talked about time and time again, first of all, it's in the older age population. Today, the 54% of all the deaths in this country are in those 75 years of age and older. If you add in the 65 to 74 year old age group, now cumulatively that comes to 76% of all deaths. However, in the 40 to 60 year old age group, it still has 20% of the deaths. So we know that we have to. Continue to target vaccine and prevention to the older age populations. But we can't. Neglect and forget those who are younger, particularly those who have may. Underlying health conditions. So Chris, to sum it up, COVID is still active. Fortunately, it's not nearly as active as it was several years ago, but it continues to throw curveballs at us. And I refuse to accept 1200 deaths a week is okay. I don't believe that's the case at all. And so for those of us who are older, who may have some immune compromising conditions, we still need to make sure that we're fully vaccinated and where we are potentially exposed to others, we should surely consider using respiratory protection.

Chris Dall: Things have been fairly quiet on the H5N1 avian influenza front. A total of 193 dairy cattle herds in 13 states have been affected as of August 26th, but the pace of new infections has slowed and we haven't had a human case reported in several weeks. But on August 30th, the California Department of Food and Agriculture announced that three herds on dairy farms in the Central Valley region were positive for H5n1. Given that California is the nation's top milk producer, how significant is this?

Dr. Osterholm: Well, Chris, I can sum up my general sense of where we're at with this situation and that quote that I use so often from C.S. Lewis. If you don't know where you're going, any road will take you there. And I feel like that's where we're at right now with this H5n1 situation. You noted the California cases. The first three affected dairy herds now reported. New Mexico just reported an additional herd. Their last one was reported back in April. What happened in those two states? Why? Why now? Is it the fact that it was not detected and it has been there the whole time? Is it the fact that there was a new spillover, potentially from bird contact, or in fact, where cattle moved around such that now introducing the virus into places it wasn't before? We just don't have any answers to these questions. And we continue to see the dairy industry largely ignore this situation. They refuse to have testing done, and they often refuse to even consider protective equipment for their workers. This really has been a challenge, I think on a scale of 1 to 10, if we're to be graded on how our response has been in this country, it surely is going to be in the lower part of the scale. 2 or 3. We don't yet know what's happening with the viruses that are showing up in these other farms in California and New Mexico.

Dr. Osterholm: Are they the very same viruses that were here three months ago? Do they represent changes? So I think in general, I feel like we just don't have an understanding of what's happening here. And now we're moving into the normal human influenza season, where in fact, we would expect to see workers coming onto these farms who they themselves may be infected with influenza. And combined with the existing H5n1 infection in cattle, will we see a reassortment occur in the udder of a cow? Could we, in fact see a human virus and a bird virus get together? As you know, and I've talked about it on multiple occasions, we now recognize that the udder of that cow has receptor sites in the udder for both human viruses and bird viruses, like pig lungs. And so this could surely be a major challenge. So I think until we have more willingness by the industry and the ability of the USDA to actually really address this in a much more vigorous way, everybody's just kind of hoping it's going to burn out. And it might, but it might not. And if it doesn't, we will all be asked the question, what did we do to actually address this? And I can tell you, and I say this very carefully and very thoughtfully, I worry that one day we could wake up and have everyone look to us and say, if you thought they did a bad job in Wuhan with COVID, look what you guys did.

Dr. Osterholm: And they would be right. I know this is harsh, but I really feel very strongly that this, in fact, is a real challenge before us that we need to get off the dime and provide a much different approach. How do we protect workers? I'll be the first to acknowledge if you're working in the dairy milking business, it's very hard to wear PPE in terms of the goggles fogging up in terms of the respirators and breathing, so we have a lot of work to do there, too. How do we devise a type of protective equipment for these workers so that they don't get infected, but also that they don't infect the cattle, meaning that again, that nose up to the next to that udder as they try to put on the clamps to begin milking. That is a risk issue today for acquiring influenza from the cattle. So we'll have to wait and see. But I think we're bungling this situation. I regret saying that I've shared these comments in detail with our national leaders in the US government, and at this point, I'm not sure that I, I can appreciate any real change in direction that is happening right now.

Chris Dall: Let's turn now to the Mpox outbreak. Roughly 4000 more Mpox cases were reported in Africa last week, mainly in the Democratic Republic of the Congo. But the real number is likely higher given the limited surveillance in the region. Mike, with the limited amount of vaccine available at this point, it feels like it could be a very long time before this outbreak is brought under control, if it ever is. What are your concerns?

Dr. Osterholm: Well, let me just begin by saying, for all the listeners out there, that listening to my previous answer and this answer think I got up on the wrong side of the bed this morning, I didn't, but in fact, it nonetheless is a very frustrating time. Just remember that with impacts we're talking about really two very different events that have occurred. Same virus of different clades, meaning that they're close relatives. But the previous experience we had beginning in May of 2022 with clade two was largely a sexually transmitted disease infection, particularly in gay men around the world. 121 countries were involved, 119 of those were confirmed, two were suspected of having cases. And when we look at that, we're talking about a number of cases that spread around the world but stayed within the context, largely of sexual contact. Occasionally cases would occur with contact with the individual. Some cases bedding or clothing might transmit transmitted, but it was not a situation that was spreading within large parts of Africa and throughout the world, as we're now seeing what's happening in Africa. So what's happening there? Well, now we have another clade of virus 1b, and today that virus appears to have a higher rate of deaths or serious illness associated with it than the other clade. Here, what we're seeing are cases occurring within the African continent, with only occasional spillover outside of that. But what does that mean? First of all, let's just look at the recent W.H.O.

Dr. Osterholm: media briefing in which there have been now over 18,000 cases of Mpox reported in the Democratic Republic of Congo or DRC. If you look at other African countries, we now have 18 countries that are seeing this very same clade, the 1b. And it's remarkable of what's happening. Drc, as I just mentioned, has this increased number, but Burundi has 702 confirmed cases and I can go down a laundry list of all these different countries. We know that surveillance is challenged in Africa just based on resources and the ability to do diagnostic testing. So surely there are many more cases out there than this. But the real challenge is how are we going to stop it? Well, we have a problem. First of all, getting vaccine to Africa, because the W.H.O. had basically resisted for some time approving the vaccines that we have that could be used against Mpox originally really largely aimed at smallpox. And there was some legitimacy to their concern about would it work differently with different clades? We just had the experience where a major impacts drug, which was thought to have worked and was used in the field with rigorous testing, was found, didn't work. So we do have a need to understand what really works or not. But the bottom line is, even with approving new vaccines in terms of their use in Africa, what does this mean practically? Well, think about this right now.

Dr. Osterholm: If you take the top three countries with cases in Africa, DRC, Burundi and Congo, collectively, that's 223 million residents of those three countries. Note, for example, 46.4% of all the individuals living in DRC are 14 or younger. Almost half of the entire country is 14 or younger. If you look at that, and that's the high risk group today with animal contact, and you look at the fact that these numbers are only going to continue to increase in population. Last year, there were 4,000,100 live births in DRC. Why is this important? Well, because right now if we look at vaccine, we have Bavarian Nordic, which makes Jynneos the vaccine that is the primary one for using an mpox. They collectively can either have on hand now, or can make, with orders being placed about 10 million doses in the next year. Now think about that. 10 million doses were. Remember, it takes two doses per person to be fully vaccinated. And I'm talking about numbers the size that we have here. And we're continuing to see the spread of this virus in this way. If we look at the United States, the source of vaccine emergent BioSolutions, has a vaccine, Acam2000, which was largely made for purposes of biodefense and a potential smallpox attack. That's a vaccine that cannot be used in HIV infected individuals or immune compromised individuals. How practical is that going to be in Africa? And again, their ability to make vaccine may even be less than that of Bavarian Nordic.

Dr. Osterholm: And then finally there's the third Japanese manufacturer of vaccine, which we only have limited information on. But what we do have suggests they too, like Bavarian Nordic, will take some time to scale up. Now, surely we could get other companies that could begin to help provide vaccine with agreements. But manufacturing is not easy and it doesn't happen overnight. And I think we're now seeing the convergence of this major transmission, which starts with animal contact, gets into humans, and now it's spreading quickly in humans. And our ability to respond with effective vaccines is just so limited. This is very reminiscent of what I just shared with this podcast, family two podcasts ago, when I shared with you the article that Mark Olshaker and I had written for Foreign Affairs, in which we laid out all the challenges with getting influenza vaccines in the next pandemic to the public because, again, a lack of manufacturing capacity. And so I think here, Chris, we can argue and debate about how many doses of vaccine. Finally, the world will contribute to Africa. But what we must never, ever forget, there's going to be far, far short of what we need. And so then what kind of plans do we have for allocation of these vaccines? Do we go to single dose and knowing that it will be not as effective, but maybe still more effective than two doses and one person and that other person? Nothing at all.

Dr. Osterholm: What do we do in terms of trying to target our activities in such a way that it's going to have the most impact? Do we give it to health care workers first to keep them on the job so they don't get impacts? And I think we just don't have a good plan. The Who's plan is not there. It's not recognizing, I think, the absolute challenge of getting more vaccine. And so stay tuned. I think this is going to be a challenge. Now, let me be clear. I don't think this is going to be a quote unquote global pandemic. Like we talk about COVID or influenza. This is not a virus with wings. While there may be maybe some limited transmission with respiratory droplet really up close contact, most of it still is going to be by far the contact kind of situation. So I don't see this as being one where, yes, it's going to run rampant around the world any more than Ebola was going to do that back in 2015, in Central Africa. But at this point, given the demographics of Africa and how it's growing and the number of people at risk for this infection, I think we got some really, really big challenges ahead of us in the future.

Chris Dall: It's time now for our ID query. In this episode, we're going to continue on a theme that we've covered over the last several episodes. When to get the updated COVID vaccine. The good news, of course, is that the updated shots from Moderna, Pfizer and Novavax are now available. So if you've been waiting for those, you can now go get them. But we've had some listeners who were infected this summer or in recent weeks, and they are wondering how long they need to wait to get the updated shot post-infection. Mike, what did the CDC guidelines say on this?

Dr. Osterholm: Well, Chris, let me just begin, first of all, with this story. And, you know, a story surely does not make for a massive study in terms of drawing conclusions. But I would like to take away at least the thought that it may actually be what I'm trying to put forward to you. Vernon and I have two very, very dear friends who are going on a bike trip in Europe, and they were leaving in mid-August. They were at more than four months out from their last dose of vaccine. And at that time, the only vaccines available were the old 2324 season vaccine. The new ones that you just talked about were not available. I said, you know, I would get it, which of course is most of the listeners on this podcast. No, I did get my old vaccine dose a month ago with the idea that I would take some protection against none waiting for the new vaccines to come. So they went and got their two doses. Well, they proceed to go on this very wonderful bike trip, and by the end of the trip in late August, six of the nine people on that bike trip had developed COVID while on the trip. Two of the three that didn't were my two friends. And was it because they got that dose of vaccine before they left? I don't know. It surely could be. But the point is, is that we do know that these vaccines, while they're not great, they're not great.

Dr. Osterholm: If they were great, they would have long term protection against a wide range of variants. But they don't. But they're really good because they can reduce you from getting ill for at least the first period of time after vaccination. But more importantly, through those first 4 to 6 months, they can greatly reduce your likelihood of getting seriously ill, being hospitalized and dying. So I want to come back to that again over and over and over again how important it is these doses are for keeping us out of the hospital. Now, for those people who have recently been infected during this late summer wave of COVID, I hope you're feeling better. We understand that with the arrival of the updated Moderna, Pfizer, and Novavax vaccines, you have a question about how can you best protect yourself after getting sick. However, studies have demonstrated that there is no significant increase in neutralizing antibodies if you receive a vaccine within 2 to 3 months of infection. In other words, you must likely have strong infection based immunity against COVID, and your body is primed to recognize the current circulating viral variant to prevent you from getting sick again, at least for several months after your infection. Vaccines aim to mimic the immunity associated with recovering from an infection. So because you already have high levels of antibodies as a defense, you'll want to wait until your immunity wanes before boosting these levels again to ensure you maximize the length of time you're protected.

Dr. Osterholm: So accordingly, the CDC recently updated their guidelines that says that you can get your updated COVID vaccine. The 2425 vaccine that Chris just referred to after three months since you became symptomatic and since you initially tested positive. So for all of you who have been infected and you want additional protection, particularly going in to the holiday season, wait three months and then go and get your over dose. However, this timeline is not set in stone. The CDC lists several factors that could be reasons to get a vaccine sooner rather than later, including personal risk of severe disease, risk of disease, and a loved one or close contact. So what is the status of those of us who have not been infected in recent months, but did have a previous dose of vaccine? Well, first of all, let me be really clear that the Pfizer BioNTech and Moderna 19 vaccines are authorized for use in people six months through 17 years of age. The Novavax COVID-19 vaccine is authorized for use in people 12 years of age and older, so at this point, anyone who has been previously vaccinated has to wait only two months to get this additional dose of vaccine, for this is now the 2425 season vaccine that just came out. If in fact you have an immunocompromised conditions, etc., you may be eligible for a second dose of vaccine two or more months again, and you'll want to talk to your physician about that.

Dr. Osterholm: But basically know that you now have the option to get these vaccines. I can't wait for my two month period to be up, which will be in just a few weeks. I'm going to go get my dose, and I would urge all of you to do that, particularly for those 65 years of age and older. You know, we can do a lot to bring these numbers of deaths down. We can do a lot to bring down the number of persons hospitalized. Please don't wait. Go get your vaccine dose. And while you're there, think about adding your children to the vaccine line. I've already talked about today. We're seeing, you know, increased number of kids in the emergency room departments. With COVID school starting. We're going to see a lot of additional activity there. So I would urge you to do that. Now we're going to include in the notes for today's podcast a document from CDC, which lays out all the variations on the theme of who can get vaccinated, when, what dose, and so forth. So take a look at that. And I hope that this good news of having all three vaccines now available should give all of us a reason to say, I'm going to go do it. I'm going to go do it.

Chris Dall: Now on to some other infectious disease news. Some of our listeners might have heard about the death last week of a New Hampshire man from Eastern equine encephalitis, which came on the heels of an announcement by Massachusetts officials that they would begin spraying certain counties for mosquitoes that may carry the virus. People may have also heard about Anthony Fauci coming down with West Nile virus. Mike, what can you tell our listeners about these vector borne diseases, the risks they pose and the context that people need to understand their level of risk?

Dr. Osterholm: Well, thanks, Chris. I'm sure that many of our listeners right now are wondering about this issue, considering how much it's been in the news recently, it seems to almost be a crisis situation in parts of the northeast. But let me try to put this into perspective. And what I mean by that is, is that mosquito borne diseases are a critical part of the public health challenges in the 21st century. I have to say that when I first got into the business in the 1970s, we were actually in much better shape in terms of controlling mosquitoes with active programs around the world. The Pan American Health Organization, along with the Rockefeller Foundation, had just literally completed almost eradicating the 80s mosquito out of the Americas. And since that time, we've seen a lot of back slippage. We've seen very little attention paid to vector control, particularly in the area of mosquitoes. And it's a very complicated and complex area. There isn't a single mosquito that is our target. There are multiple types of mosquitoes that have very different habitats requirements. They have very different ways in which they transmit infectious agents and how they live with humans. And so let me just try to put some perspective to this. So yes, in fact we do have this case of triple E as it's called eastern equine encephalitis. But I'll come back to that in a moment. But first let me cover the really biggies, the ones that are the challenges. And I think this is a situation here today where I'm trying to share with you kind of the context of what kills us versus what hurts us versus what concerns us versus what scares us.

Dr. Osterholm: And oftentimes they are very different, all four of them. And today, I think some of that is the case with this. If I had to pick the big ones right now, I'd focus on the Americas. And when I say the Americas, I'm really talking about northern, central and Southern America, because in fact, we're all connected here. And as you'll see, we have a lot of people who are citizens or live in the United States who visit parts of the Americas that result in serious health problems due to mosquito transmitted viruses. So what are we talking about? Well, if we look at viruses like yellow fever, Zika or approach, any number of these infections are occurring at a very, very high rate around the world and particularly in the Americas. Right now, there are 92 countries that are have dealt with Zika over the last 5 to 7 years. If you look at Brazil, we're now at an all time high, 70 year high for several infectious agents transmitted by mosquitoes, notably yellow fever. And we're talking about many thousands and thousands of cases which are important. So let me just try to go through what I think are some real challenges for us, and then tie it up with the triple E summary. Well, if you look, first of all at dengue, dengue is a fascinating disease transmitted by the Aedes mosquito.

Dr. Osterholm: Now I'm going to emphasize Aids because it's a very important difference from many other mosquitoes. The Aedes mosquito has often been called the household mosquito. It loves to live around people. And why? Because we make every opportunity to provide places for them to breed. Discarded plastic, water holding containers, any number of things that they want. Very quiet, almost dark like conditions. And they want to be close to us. And a mosquito will literally not fly across an open field or a major city parkway. That's how they reside. So when you have disease transmission with a virus transmitted by the Aedes mosquito, you can pretty well count on the fact if somewhere close to you. This mosquito also is a daytime biter, not a nighttime. When you're sleeping, you'd think, well, that should make it easier to keep it away. No, because they bite you behind the neck. They bite you behind the elbow, in the back of the legs, places you don't feel them biting. And so they really live quietly with you. And that's a real challenge. Now that's also, though, lends itself to control. But why has dinghy taken off? Because, in part, urbanization of the world, we now have so many locations that have so much plastic and garbage and junk that just make ideal breeding sites. So that discarded wrapper from a fast food restaurant now in the ditch becomes an ideal breeding site with enough shade and ongoing rainfall.

Dr. Osterholm: When you look at the issue of tires, last year in this world, we abandoned 1 billion used tires and in many cases these were just thrown in junk piles. These were ideal breeding sites. Water gets inside that tire from rainfall, and it is the most protected, wonderful place for Aedes mosquitoes to live. And in fact, the mosquito Aedes albopictus, like unlike Aedes aegypti, is new to the North American continent, arriving in the late 80s early 90s on ships bringing used tires back from China that had been retread there and set out in fields before they were loaded into ships, bringing the mosquito with them now. Aids is huge. In the first five months of 2024, we've already had over 7 million cases diagnosed around the world. Now that is not a lot in one way when you think about the world's population, but this is just a minimal, minimal, minimal estimate because of the lack of diagnostic capability in much of the world right now, half of all the globe are at risk. And it was estimated that anywhere from 100 to 400 million cases of dengue occur each year. Now, what makes dengue really a challenge is not the initial infection, called breakbone fever, caused by one of four serogroups of the virus prior to World War Two, these four serogroups were equally distributed around the world in different locations but not overlapping. So for example, in Northern Asia, Southern Asia, Africa and South America.

Dr. Osterholm: And it was only with commerce and World War two that we suddenly saw these mosquitoes being moved to all the locations around the world. So where there's one dengue serotype today, there's actually all four. Dengue hemorrhagic fever occurs when you've been previously infected with dengue and you have some antibody, but not enough to protect you from getting infected again, but also enough so that basically it can cause what we call immune enhancement, where your body recognizes this new serogroup and it triggers this very severe immune reaction, which results in this hemorrhagic fever. Dengue hemorrhagic fever is one where about 5% of the severe cases end up dying from it, and it's one that, in addition to being transmitted from mosquito to human, can also be transmitted to the unborn child. It can be transmitted in blood products as well as an organ donation. This is only going to continue to become more and more of a challenge, as we see the conditions for Aedes mosquitoes around the world is only increasing dramatically in their habitat that they need, as we have a junkyard society. We will continue to see these problems. Let me just conclude on what the risk of dengue is to the United States itself. We've already had cases that were locally acquired detected in Florida, Texas, Hawaii, Arizona and California. It's very likely that that number of states will only continue to grow. We'll have more and more individuals who will be in countries where dengue is present, and they will then bring it back with them.

Dr. Osterholm: Mosquitoes will feed on them. Start a local infection cycle going on. Right now there are. Dengue is common in six US territories and freely associated states, including Puerto Rico, which just this past year declared a national emergency because of the number of dengue cases. It's an American Samoa, the US Virgin Islands, the Federated States of Micronesia, the Republic of the Marshall Islands, and the Republic of Palau. And I can tell you, it is wide widespread through the Caribbean and into South America. So as travelers, we have to also be mindful of that. Let me move to another one that has received a fair amount of attention over the course of the past couple of weeks, in part because my dear friend Tony Fauci was a case of West Nile virus infection, and one that I must say was a pretty severe case. But at the same time, we wish him well and know that he's recovering. But it really raised the issue of just what is West Nile virus and what's happening. This one is actually transmitted by a different mosquito, the Culex mosquito. Unlike the Aids mosquito, this one will fly long distances from where it's hatched. So if you try to control all the aspects of breeding sites in your local environment, your neighborhood, your your home, this thing can still fly many miles in a given night on the winds, and we're very familiar with that here in Minnesota.

Dr. Osterholm: And I've actually participated in studies on Culex mosquitoes. And looking at how far in a given night they'll fly. If we look at what's happened so far. West Nile virus arrived in the United States in 1999 from Israel and within short order, within a few years, it literally had spread to all 48 states. One of the reasons why it spread so quickly is because birds play an important role in developing viremia when mosquitoes feed on them, particularly the fledgling birds in the spring and early summer that can't fly out of the nest. And then they get infected, which in some cases can actually kill the bird, and then they are fed upon by other Culex mosquitoes who are yet uninfected. And it just takes the whole cycle and it ramps it up throughout the summer. Each cycle just gets more and more and more virus in that given area. Right now, it's in all of the 48 lower states, and it's one that we see more and more evidence that this is going to continue to grow. And it's important about 80% of all the cases of West Nile are asymptomatic. And if you look at when we hear about this number of people who get severe illness, about one inch 150 of all cases overall get severe illness. It can leave you with a neuroinvasive condition, meaning that it actually can impact on your brain. And this is one that is a serious challenge when that happens.

Dr. Osterholm: Overall, there have been 377 cases reported in 2024. 255 of these were the Neuroinvasive human disease and the reported from 38 states. This is such a gross underestimate of what's going on. Just think about the fact that if we talk about 255 cases and only about one inch 150, develop this, you can see that there have been many more times, more cases out there that have not been detected. And also we're still at the peak season. It's often late August, early September, where that cycle of bird to mosquito, bird to mosquito, with Occasionally those mosquitoes then feeding on a human actually builds and builds, and so expect that we're going to see more West Nile virus transmission. I also want to note that much like dengue, West Nile virus can be transmitted from infected mosquitoes, but also transfusion transplants and mother to child, as I noted earlier. And this is rare, but these can these modes of transmission do occur. So West Nile surely is a significant challenge. Another of the arboviruses that are a real challenge is one that is actually near and dear to my heart, and I say that with a real frown. This is La Crosse encephalitis. Named after La Crosse, Wisconsin, a community not far from my hometown where I was raised in Iowa. This is a mosquito of transmitted disease. 80 Triseriatus is the primary mosquito, the treehole mosquito. It loves hardwood forests where you have tree crotches where a two tree limbs split off and water collects in that little space between them makes for ideal breeding sites.

Dr. Osterholm: I worked on this disease as a sophomore in high school, collecting mosquitoes for the Iowa State Hygienic Lab. I got pretty good at sorting out and identifying mosquitoes by species, because we had a number of cases across encephalitis in our area, primarily in young children, and in each instance we could win a case occurred, could identify actually the likely source by just doing a detailed search of the area where that child most often was at usually plain. One of the things that was a major risk factor was tires used for swings without any holes punctured in the water would collect, and the mosquitoes love that environment. It was also a very significant issue for me in that when my son was 15 years old, he developed La Crosse encephalitis as a result of an exposure to a new home we had just moved into To on the lake here in the Twin Cities, and unbeknownst to us, the home had been carved into this woods. And there, in those tree crotches near the lawn of our house, was an 80 triseriatus mosquito. And there, in the area just immediately beyond our lawn, were trees with the tree crotches. I talked about that and not only had the 80 triseriatus mosquito, but they also were infected with virus. We learned that later. My son was actually in the intensive care unit at that time with his infection.

Dr. Osterholm: Needless to say, it brought home the reality of the situation. Today, we've actually eliminated a lot of La Crosse encephalitis in areas like the hardwood forest because once we recognize the localized focus, if you did a ground search and could take away those breeding sites, in the case of our trees in our neighborhood, they were all at eye level or below. And in each instance we just filled them with sand and they never again produced these mosquitoes are as to. To date, there have been 14 cases reported in the United States. 13 of these were neuroinvasive human disease cases, meaning that there was a lot of mild or asymptomatic cases out there that never got counted. Four states have reported cases. Most of them are in the Appalachian area. And they continue to be a challenge. And then finally, let me just conclude on eastern equine encephalitis, as I've laid out all these diseases, and they are just a partial list. But to date we've had six cases of triple E, six of these were neuroinvasive in five different states, all largely in the northeast, except for one case in Wisconsin. Now, when we look at this, this is a different another different mosquito. This is one that cheilosia mosquito which is responsible for transmitting the virus from birds back to the mosquito, vice versa. So in terms of the response to eastern equine encephalitis, I think most people would say yes. The death was very unfortunate.

Dr. Osterholm: But when you look at the burden of vector borne diseases in the United States right now, eastern is way at the bottom of the list. And yet, based on what we've seen happen over the course of the past two weeks, you would be certain that, in fact, this was by far the most significant public health challenge with vector borne diseases. And they're just not. So what can we do about these? Well, you clearly can protect yourself by using repellents. And most people think of the repellent Deet, which surely has been effective. But also it is one that leaves an oily kind of feel to it has an odor to it may degrade certain plastics. And so I surely don't want to discourage you from using it. It's been proven to be safe and effective. But there's also now another option, picaridin, which is now used by many of the repellent Manufacturers, and this was a product that came out of Germany in the 1980s, where there was an attempt made to provide for a more user friendly type of repellent. This one has no odor, has does not have the greasy feel, does not break down plastics, and can also be just as effective as Deet. So you may want to take a look at that very issue is a type of repellent you use if you use it, particularly at dusk and dawn when the mosquitoes are most active, you can greatly reduce your risk of being bit.

Dr. Osterholm: In addition to that, the 80s mosquito again can be removed from an environment. If you just make sure that you don't have standing water, you don't have locations that even like a watering can that sits underneath a porch which has some water left in it, is an ideal breeding site. Um, if you notice that there are other kinds of water collection areas around you, as I mentioned, the tires, but also anything else garbage in general that can serve as a place for water to sit and for mosquitoes to breed. Get rid of that stagnant water. So I just leave you with the fact that mosquito borne diseases are only going to get to be more and more and more important, they're going to become very important over time, as we see this ever increasing number of cases. And with climate change, we're already realizing that there will be changes in where these mosquitoes actually now live. For example, there are some modeling evidence to suggest the Amazon basin is going to actually see less rainfall, less likely to have more mosquito habitat challenges where in certain parts of Asia and Africa, it's going to be just the opposite, and it's going to even be more likelihood of heavy rainfall. We're beginning to see these patterns in North America, so stay tuned. Mosquito borne diseases are very important. We could spend a number of sessions here just addressing the issue of mosquito borne diseases. What they do and how do we control them.

Chris Dall: Now for this week in public health history. And my guess is that we're going to have something that's related to vector borne diseases.

Dr. Osterholm: Chris, you read my mind. Thank you. This is one that's actually, uh, near and dear to me, and I'll explain why in a moment. We're keeping with the theme of mosquito and vector borne diseases. This week, September 10th, 1913, marks the 100th 11th anniversary of the completed excavation of the Panama Canal. This monumental feat of engineering made trade and transportation safer than the alternative path around Cape Horn, but its construction came at a very significant cost, not just financially but also in human life. The concept of building a canal across the Isthmus of Panama can be traced as far back as 1513. It wasn't until the late 1800s that the French engineer Ferdinand de Lesseps, builder of the Suez Canal, would break ground. However, the job proved to be far more difficult than expected. More than 22,000 workers died from tropical diseases, primarily yellow fever. The doctors at the time didn't understand well enough to prevent and control. The mission was abandoned until 1903, when the United States gained control of the Canal Zone. If the US effort were to succeed, they needed to tackle two primary challenges engineering and public health. The cutting edge research on the tropical diseases at this time period was taking place in Havana, Cuba. There, Cuban epidemiologist Carlos Finlay and notable U.S. Army surgeon Walter Reed built the scientific foundation for understanding both the yellow fever and typhoid. Soon after, Doctor William Gorgas was appointed as the chief sanitary officer in the region. He instituted strict mosquito control measures in Havana and rid the city of yellow fever in three months. He brought those measures to Panama, which included draining standing water in ponds and swamps, widespread fumigation, use of mosquito netting, and construction of potable water infrastructure. It is estimated that these measures save thousands of lives from yellow fever, typhoid, and malaria.

Dr. Osterholm: Still, over 5600 workers died during the US construction of the canal. Despite advances in technology and scientific understanding, the legacy of the Panama Canal is steeped in racism and colonialism. In Gorgas own words, the project was, quote, a conquest of the tropics for the white race. Us efforts to control the mosquito borne disease were confined to areas inhabited by white Americans, while black, Asian, and indigenous residents and workers remain vulnerable. Even today, public health significantly underfunds what are considered neglected tropical diseases, which primarily affect poor communities living in the global South. I hope this piece of history helps us to learn from our past and move forward towards global health equality. Now, I mentioned at the outset that I had some interesting connection here. I had the good fortune several years ago to be part of a team of individuals that went to Cuba to evaluate their COVID vaccines, quite remarkable vaccines. And I think the world would benefit immensely from seeing them come forward. But what I got to spend time at the Finlay Institute, named after Carlos Finlay, and it is a remarkable group of experts in Cuba working on a number of important infectious diseases. And they notably came forward with a vaccine that nobody else in the rest of the world had. So it was a pleasure to be there with them. I was very impressed by my Cuban research friends, and all I can say is is that in fighting public health, we all are in this together and it really is a need on a worldwide basis to join hands with anyone that can help contribute. And clearly the Finlay Institute in Havana can do that.

Chris Dall: Mike, what are your take home messages for today?

Dr. Osterholm: Well, I bet you'll never guess that my first one is about COVID. It really continues to be a community risk issue, but one that is very different today than it was several years ago. Yes. While we continue to see major transmission of this virus throughout the world, it is fair to say that the number of severe illnesses per number of infections has dropped precipitously. And that, again, I think is accumulating some human immunity that's causing that to happen. So what we have to do now is really adjust our approach. What is it all about now? And it has to be really based on the vaccine. We can't change how fast these mutations occur and which new variants emerge and what that means in terms of our previous immune protection. You know, we don't think twice about getting a flu shot every year because the virus has changed some. We've got to continue to get that mindset that we need to consider getting vaccinated when the virus changes. With COVID, not once a year could be twice a year, but that could be a big, big, big step in reducing the serious illness, hospitalizations and deaths we see in our older populations, particularly targeting things like long term care facilities and so forth.

Dr. Osterholm: So we need to really push what we know works and, you know, let society live its life as they do right now. Nobody's trying to change that or take that away from them. But what can we do to target those who are still getting seriously ill? You know, I said this in an early podcast back in 2020. It got me in a lot of trouble because people misinterpret it. But I said I'd I'd love the day that everybody got COVID twice a year in terms of infection, but because it had become such a mild illness, there was nothing more than the common cold. Nobody died from it, and I feel the same way. Yet today, if we have lots of COVID out there, but with very little severe illness, that's what we're really trying to accomplish. And so the vaccines surely can help us that way. In terms of mosquito borne diseases, you know, mosquitoes actually are the single most dangerous animal on the face of the Earth. They kill more humans than any other animal species out there. And we have to understand that as the world is seeing this major increase in everything from malaria to dengue to all the different diseases that we've talked about, we are seeing more impact on high income countries as these mosquitoes also make their way into locations in those countries, as well as for the travelers that we, as so many of us do, travel around the world.

Dr. Osterholm: So mosquito borne diseases are going to continue to be front and center. I'm happy to report that soon, for the vast majority of North America, they won't be a big problem for a few months. That's, I guess, the one trade off for the snow and cold. And then finally H5n1. Uh, what a mess. We need to know a lot more. Uh, I don't know where this is going to go. I don't know if we are going to just see it fade away one day, or will it continue to persist in such a way that matches up the H5n1 virus with the human seasonal flu virus and creates a brand new one, which could be a disaster of disasters? I don't know, but I know that we're not going to stop that opportunity from happening if we don't, in fact, do a better job of understanding what's happening with H5n1 in our dairy operations around the country.

Chris Dall: And what is your closing song for today?

Dr. Osterholm: Well, having received pictures this week of my grandchildren all heading to the school bus in their new clothes. One of them needed desperately to get new clothes, as is his. He's at that age where he outgrew his pants by three inches this summer. Um, it's just a remarkable time to watch that and to see the excitement in the kids. But also it's about what is we as parents do when we have that happen and how do we feel, and what does this all mean for us? And Neil Young wrote a song for his daughter, Amber Jean, who is 21 years old in her last year of college. And in this song. Here for you, he talks about how he'll always be there for her and misses her. He sings that he never wants to hold her down, but he'll always be there if she closes her eyes. The song really explores the complexities of being a parent watching their children bloom into an adult. Yes, I'd miss you, but I never want to hold you down. You might say I'm here for you. Neil sings, expressing both his absolute love and his unconditional faith in his daughter. So here it is. Here for you, part of Prairie Wind, his 28th studio album that was released in September 27th of 2005. The song is here for you. When your summer days come tumbling down and you find yourself alone. Then you can come back and be with me. Just close your eyes and I'll be there. Listen to the sound of this old heart beating for you. Yes, I'd miss you. But I never want to hold you down. You might say I'm here for you.

Dr. Osterholm: When the winter comes to your new home. And snowflakes are falling down. Then you can come back and be with me. Just close your eyes and I'll be there. Listen to the sound of this old heart beating for you. Yes, I'd miss you. But I never want to hold you down. You might say I'm here for you in the spring. Protective arms surrounding you in the fall. We let you go your way. Happiness I know, will always find you. And when it does, I hope that it will stay Neil Young. So thank you very much again for spending another podcast with us. We appreciate it. I also want to acknowledge the podcast production cast, particularly Sydney Redepenning, Elise Holmes and Chris, uh, for their work on this podcast. And I want to thank you as a listeners for all the feedback and comments we get. You help make us better. Uh, if we're not getting better, that's our fault, not yours. You've surely provided us with remarkable feedback. And again, I just want to share with you the need for kindness. Um, if there was ever a time. Now is it? And so, uh, it's one of those things where it's so easy to do. You just don't do it. So do it. And two weeks from now, and we have the podcast and your return, you can say to yourself, I did do that act of kindness. Yeah, it kind of surprised everybody, but it was kind of interesting. So do it. Meantime, I hope you all stay safe. Go get those doses of vaccine. And just remember how much we appreciate you. Thank you very, very much.

Chris Dall: Thanks for listening to the latest episode of the Osterholm Update. If you enjoy the podcast, please subscribe, rate and review wherever you get your podcasts, and be sure to keep up with the latest infectious disease news by visiting our website CIDRAP.umn.Edu. This podcast is supported in part by you, our listeners. If you would like to donate, please go to CIDRAP.umn.edu/support. The Osterholm Update is produced by Sydney Redepenning and Elise Holmes. Our researchers are Cory Anderson, Angela Ulrich, Meredith Arpey, Clare Stoddart, and Leah Moat.