Cyclospora: Then and Now

Chris Dall: Hello and welcome to the Osterholm update, a podcast about infectious diseases and public health featuring 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 over 50 years of experience in infectious disease epidemiology to provide straight talk on the latest infectious disease outbreaks, counter misinformation and disinformation about vaccines, and distill the complex and ever evolving public health threats facing our world. 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. A little more than 19 years ago, an epidemiologist with the Minnesota Department of Health wrote an editorial in the New England Journal of Medicine about a 1996 multi-state cyclosporiasis outbreak linked to imported raspberries. Here's an excerpt from that editorial: "We need to establish well-defined criteria for evaluating the quality of epidemiologic data from investigations of outbreaks, particularly when the etiologic agent is not readily isolated from the implicated food product. Furthermore, when a widely distributed product is implicated in an outbreak, we must ensure that before public announcements are made, all available epidemiologic and microbiologic evidence and information on the product distribution are reviewed quickly, and that the conclusion is supported by federal, state and local experts in foodborne disease." That epidemiologist, as you might have guessed, was Michael Osterholm. And what he wrote in that 1997 editorial could very well be applied to the current multi-state cyclosporiasis outbreak, which has also been linked to a widely distributed product. But it doesn't appear that any lessons that he tried to impart have been followed. The cyclosporiasis outbreak, and the way it's been handled by federal and state officials will be the focus of this episode of the Osterholm update, episode number 214. We'll also provide an update on the Ebola outbreak in the Democratic Republic of Congo, discuss the ongoing measles outbreaks in the United States, evaluate a potential uptick in U.S. COVID cases, and bring you the latest installment of This Week in Public Health history. But before we get started, as always, we will begin with Dr. Osterholm opening comments and dedication.

Dr. Michael Osterholm: Thank you, Chris, and welcome back to the podcast family, to another edition of the Osterholm update. As I say each and every time and meant with heartfelt gratitude. We appreciate the feedback, the messages you send us, even the meeting you on the street and just being able to chat informally about what we do here means a lot. And I just want to emphasize one thing that I think is such an important part of our relationship today, we are seeing more and more venues for information and critical information, but it's behind a paywall and we are absolutely committed to never having that happen. We will never have a paywall, and we believe that information like this should be readily available to everyone, not just a few that can pay. So thank you very, very much for what you do to support us. And most of all, I also want to say, I hope that the information that we're sharing today and in the future is what you're looking for today. I want to start with a dedication that's very personal to me, and you'll see why in a moment. It touches on something very close to home I want to dedicate this episode to anyone affected by the wildfires in Ontario, Canada and northern Minnesota in July.

Dr. Michael Osterholm: There have been over 150 wildfires in Ontario alone, which have burned more than 1.8 million acres of forest, more land than the size of the entire state of Delaware. The Guardian reported that the wildfires have burned two First Nations communities to the ground in Canada. Many First Nations leaders reported they had to self-evacuate without any help from the government or emergency warning. In fact, the Canadian federal government had initially told them there was no imminent threat of danger. In northern Minnesota, wildfires continue to blaze in and outside of the Boundary Waters Canoe Wilderness Area. Over 1000 firefighters from all across the country have come to help try to contain the 18 fires in the midst of the record level heat waves. This was very personal to Fern and me, as we have an 80 year old cabin that sits in the Superior National Forest adjacent to the Boundary Waters Canoe Area. Today, those firefighters are literally the block between that fire and our cabin. We so appreciate these firefighters. Many of these wildfires are in extremely remote areas, which makes containment difficult, if not impossible. These fires have burnt down communities, exhausted, understaffed firefighters and flooded numerous states and provinces with hazardous smoke. It also has been a very challenging time for firefighters, as many of the days of the last several weeks here in Minneapolis/St. Paul, as well as in northern Minnesota, we've had temperatures approaching 100 degrees.

Dr. Michael Osterholm: Try fighting a forest fire with lots of smoke and those heat conditions. It's remarkable what they do. We're reckoning with the climate crisis in real time. Anyone who says climate change is a hoax only need. Look at what's happened in the last 40 years with wildfire burned throughout the world. During that time, there's been an increase in major wildfire activity in Canada, Russia, South America, Australia and even Europe. Today, we're watching what's happening in France and Spain in disbelief that such a fire could happen. Today, we're thinking of everyone who has lost their home, whose air has been affected, and those who have put themselves on the front lines to fight these fires. We're thinking of all of you and we are mourning beside you. Let me move on to that very, very popular or unpopular topic area called sunlight. For those who want to take their 32nd respite, please do right now. Today in Minneapolis, Saint Paul sun rises at 5:56 am, sunset at 8:41 pm. That's 14 hours, 45 minutes and 27 seconds of sunlight. But we are losing sunlight at two minutes and 19 seconds a day, and it's been sometimes difficult to see that sun with so much smoke in the skies that it's made it almost impossible to imagine that the sun is there.

Dr. Michael Osterholm: Somewhere up in that sky. Now to our dear, dear friends in Auckland, New Zealand, at the Occidental Belgian Beer House on Vulcan Lane. Your sunrise today is at 7:21 am. Your sun sets at 5:33 pm, ten hours, 12 minutes and 27 seconds of sunlight. You are gaining sunlight at about one minute and 37 seconds a day. Wonderful. Now, there has been a lot of discussion in the last several weeks about what to do about daylight savings time. Now remember, the sunlight is going to be the sunlight. We can't change that in the sky. We can only change our policies about when we consider something on the clock to match up with something that's happening in the sky. And in our next podcast, we're actually going to take this on as one of the topic matters. Is there a public health implication to sunlight and daylight savings time? Well, I'll give you a little bit of a hint. There is. So we'll talk about that in the next podcast about the whole issue of Daylight Savings time and what it means for public health.

Chris Dall: Mike, let's begin with an update on cyclosporiasis cases, because this story has been evolving rapidly and we now have additional outbreaks. So what do we know at the time of this recording?

Dr. Michael Osterholm: Chris, I'm sure many of our listeners have the same question, but the reality is the picture is still evolving. Before we dive into the latest developments, let's just take a step back to give a quick background to listeners who may be tuning in. Cyclospora is a microscopic parasite that people typically pick up through exposure to contaminated food or water, most often fresh produce. Symptoms usually begin about a week after exposure and primarily include prolonged GI complications consisting of diarrhea, cramps, and loss of appetite. It's also notable that once you excrete the parasite in your stool, it actually takes 10 to 14 days before that parasite is mature enough for it to actually infect another human. So that's why we say that this particular parasite is not a person to person transmitted agent. Yet at the same time, it does come from one person, but it's in the environment for at least seven or more days before it's mature enough to actually cause illness. So what does cyclosporiasis mean in the United States? Well, cases tend to spike during the summer months, and this year's outbreak really first drew national attention as case numbers surpassed anything we'd seen in previous years. And investigators began linking illnesses across multiple states to fresh produce exposures. It's notable that we often see cases every spring in early summer, also from people who are foreign travelers coming back to the United States. So that does not imply a foodborne source here, but rather that these are cases that we just need to understand are part of the everyday picture of cyclosporiasis spread around the world. At the time of this recording, the CDC has received reports of more than 4100 laboratory confirmed cases of cyclosporiasis since the beginning of May, at least in nine states, while over 300 people have required hospitalization. There have been no reported deaths attributed to the outbreak. There are also an additional 7,400 probable illnesses that have been reported, but not yet confirmed, because of the delays in reporting and the time it takes to complete testing. We believe the actual number of illnesses is substantially higher than the official count we have now.

Chris Dall: So Mike, let's talk about the outbreak response because I know you have a lot of thoughts on it. Where do you think things have gone wrong?

Dr. Michael Osterholm: Well, let me begin by saying that under the best of conditions, this is a very, very difficult outbreak to actually investigate and to come quickly to a conclusion as to what was happening. So I don't want any of my comments to be in any way suggesting that this was easy. It's not. However, as you noted in the introduction and the editorial that I was asked to write for the New England Journal of Medicine almost 20 years ago about the first outbreak of Cyclosporiasis in the United States in Guatemalan raspberries. It was interesting how many things we've learned since that time about foodborne disease and specifically around cyclospora. Yet at the same time, it feels like we haven't learned all that much. For example, in the 1996 outbreak, several state health departments went off on their own, doing their own analysis of what happened, and they concluded that strawberries were the vehicle for which the cyclospora parasite was entering into the food supply. Well, it wasn't that was premature. It turned out to be Guatemalan raspberries, and that part was confirmed. Now, why do I even mention this? Because part of the issue around public health obligation is to like medicine, do no harm. And in that case, we harmed the strawberry industry substantially with incomplete information and the conclusions that led from that information. And so we always want to be certain that we're right, that we actually have called the right call. But that does not mean to be timid.

Dr. Michael Osterholm: That means to take the data you have and pull it together in a way that you can make a cogent argument why this is or isn't the reason for this outbreak. And during this particular outbreak, we saw such little leadership on behalf of the federal government and even in some of the state health departments about making recommendations that, in fact, were tested against the reality of what was happening. For example, we continued to see individuals both from academia, from government, comment on how to disinfect your produce from cyclospora, and there is no suitable means beyond heating to 158 degrees. Or food irradiation. Food irradiation, of course, will not be used because of people's fear of what it does to food, which of course is not true, but nonetheless, it's something we have to live with. But the part that I have had real concern about is how we have had so many what have become television newspaper experts that have no expertise in this business whatsoever. You know, as I've shared in the previous podcast, I have served as an advisor to Fresh Express, one of the produce companies in this country, a company that has been intensely committed towards food safety. And yet we know that those challenges are there for the food industry. But what do they know? What can they tell us? And did you hear anyone from the industry really speaking out during this recent outbreak.

Dr. Michael Osterholm: Did you hear people asking, what data do you all have in the industry to help support what's going on? For example, we had very, very few people who really understood the supply chain issues around produce. And what do I mean by that? Well, when you think of agriculture and you think of crops, corn, soybeans, etc. It's harvested once a year. A very limited couple day harvest is stored in grain bins, wherever. And that's it. With produce, it's harvested every day of the year, and fields are planted accordingly to come into that period for cutting basically at a very specific time. And this is all part of a very large ranch block system, blocks being part of ranches that it's all planned out when the crop is being planted, so that they know exactly when it could be harvested so that you would have your product the next day. Now we know with cyclospora that in fact, the primary means of transmission is via contaminated food and water. We also know that as humans, if infected with the parasite cyclospora, when you excrete it out in your stool, it still takes 10 to 14 days of maturation outside of the human in order to be able to infect other humans. So someone who is ill with cyclosporiasis today would not have infectious parasites in their stool. But 12 to 14 days from now, wherever that stool appears. Now there may be now live viable cyclospora spores that could infect a human.

Dr. Michael Osterholm: This entire picture was largely missed because if you wanted to understand, first of all, what kind of an outbreak you're dealing with, I have always looked as age as a very, very critical factor for understanding what's happening. And what do I mean by that? Well, when you see an outbreak where only 5% of your cases are age 20 or younger, despite the fact that this age group makes up 25% of the population, you know that it's underrepresented. What does that tell you? It's some kind of a vegetable. It's a leafy green. Why do I say that? Because kids avoid it. On the other hand, if you're dealing with an E coli outbreak in hamburger, you might very well see 30 or 40% of the cases in kids at that point. That then tells you that's a different kind of outbreak. We knew early on that this was likely a produce outbreak. We know from previous years that this is the time of the year that we typically see cyclosporiasis show up in our communities because of imported products, or even, in some instances, leafy greens grown right here in the United States. When this outbreak happened, we did not have a national coordinated response. CDC was very late to the draw and bringing their expertise public, namely in the Health Alert network that was not published until July 14th, almost six weeks after they began working on this outbreak.

Dr. Michael Osterholm: In the past, a Han or a health alert network would have been sent out to all health departments at the very first instance of an outbreak to alert them to it. That didn't happen here. And then, as a result of all of this, people continued to mischaracterize how to talk about this outbreak. Well, first of all, I'm going to put a caveat around it and say I think it's several outbreaks all happening at the same time. Originally, we had the five states that were centered around Michigan, Ohio, Indiana that were really hit hard. Now, again, as an epidemiologist, that tells me a lot because that's a distribution area and you can begin to understand what food products are coming into that area for distribution, as opposed to being served out of a distribution service in the northeast or the southwest or Western Midwest or the West. That tells you a lot of information right there. And it was clear that this fit a pattern that we'd seen in the past with other produce items and cyclospora. Now to date. CDC is reporting 4,100 cases. We know that that number is substantially higher. Michigan alone says they have over 8,000 cases. And I think that's true, that we're going to see in the end a lot of cases. But it took up until last Friday for CDC to actually finally publish what we call an epidemiologic curve, which plots the cases out by a given, whether it be age or time or whatever.

Dr. Michael Osterholm: And they plotted it out by when people actually became ill, what was their date of onset, which of course we know is about 7 to 10 days after they actually ingested the parasite. When you look at that, it turns out that there was a peak of cases that occurred building from early June to June 24th, when 157 cases were reported that day on July 2nd. It dipped way back down to 19 cases, and then on July 9th, it went back up again at 152 cases reported per day to the CDC. We will provide a link in our show notes to this particular document. So you can see this is a bimodal situation. It's remarkable. The first wave clearly ties in closely with what happened with Taco Bell and the shredded iceberg lettuce. But the second wave, we're not sure what that means. As I said three weeks ago, I was convinced there were multiple outbreaks going on. I think that those were two overlapped outbreaks. We'll find out. But in the meantime, what happened is the media, again, poorly informed about this outbreak and what it means, kept piling more and more data on states where cases are reported from showing how this was spreading throughout the United States. Well, number one, we always expect cases this time of year. Minnesota. As of right now has over 60 cases of cyclosporiasis largely tied to international travel.

Dr. Michael Osterholm: That's not unusual. Texas was the same way. California, a number of states like that. But every time a case would show up, this would get added into the media's pegboard, saying, look at see it spreading or giving you the sense of spreading when in fact that was not the case. It was occurring basically by when things got reported. A good example, two of the states that are now part of the nine states that have been reported to be part of this outbreak, reported only in the last week and a half. Their information nonetheless, these outbreaks occurred weeks ago. Again, no one was really keeping track of time, place and person. So one of the lessons we have to learn here is with cyclosporiasis is that because of the time period it takes to actually be documented to be a case, meaning I ingest the parasite Seven days later, I may get sick. I may be sick for days before I go in and actually am seen. And then once I'm tested, it may be five or more days before I get a test result back. And so you can actually see also that when a case was exposed or when they were had onset, sometimes has no reflection at all when they get reported. And then the media is now becomes aware of them. So one of the messages I think that comes out of this is we need to do a much better job of communication.

Dr. Michael Osterholm: I'm happy to report earlier this week, Dr. Jess Stier actually wrote a beautiful piece on the communication issue. It's a CIDRAP op ed piece that's linked in the show notes. I can't emphasize enough how important good communication is in an outbreak like this. And let me also just add, why does public health get themselves in trouble? Because we had some states and we had some individuals in public health making claims that you could use X, Y, or z to disinfect your produce from cyclospora by head lettuce. Cut the outer three leaves off, then wash it. There's no data to support that. That's an effective means of eliminating cyclospora. The other things that came up about washing your product in the sink, we actually have data showing that the triple wash product that's in bagged lettuce actually is safer when it's actually taken out of the bag and consumed directly, not washed again because of the risk of becoming contaminated while in that kitchen environment. But that kind of information was never shared. We just kept hearing  "don't buy bagged lettuce." Now, why is that important? Because as I mentioned, with the strawberry situation and the outbreak in 1996, what we've watched happen in this country is basically a wholesale retreat from leafy greens. Prior to this outbreak, on average, over 150 million servings of leafy greens happened every day in this country. It's a food that we want people to eat because it's a healthy food.

Dr. Michael Osterholm: Yet what happened is at least a 40 to 50% drop in the market during this time because of this information about, well, if I can't be sure. Well, when I look at the outbreaks that have happened relative to the big outbreak, meaning kind of the mini outbreaks in a given state, there were many areas of this country where we had no evidence that cyclosporiasis was occurring at any unusual rate beyond expected. Yet we were giving general information to these people, "Don't eat lettuce." That to me is comparable to what we did in COVID when we said "Well, if you just stand behind this plexiglass shield, you'll be fine." It was just bogus information. So one of the things that I hope will happen with all of this situation now is, number one, we will recognize there were many, many mistakes made in investigating this outbreak and that we can learn from these mistakes. And I hope that we can do a hot wash or a review of this outbreak, not to point fingers or to blame, but to help people understand what could we have done differently? How could we have done it differently? And to date, we just have not committed ourselves to really understanding what went wrong, what it means, and how do we fix it. We're going to continue to, unfortunately, suffer these kinds of outbreaks for which really that is unnecessary.

Chris Dall: Mike, as you've just noted, poor communication from federal officials has opened the door to a lot of incorrect information for consumers. And we've been getting a lot of questions from our listeners about what they should be doing. So that's our ID query for this episode. What should people be doing to avoid this parasite?

Dr. Michael Osterholm: Well, Chris, as I just noted a moment ago, we have to remember that the consumption of leafy greens in this country is really a remarkable event. On average, 150 million servings a day. And thankfully, we actually have access to leafy greens like this as part of a healthy diet. When you look at this outbreak, which I want to not minimize for a moment, this is a very important outbreak, and I am very concerned about those who have become infected and are suffering as they are. But when you put this into perspective, think about the fact that that 150 million servings a day corresponds to over a billion servings a week. Now, if you actually look at even a number, that's greatly increased from what we see right now with the cases, instead of 10,000 cases talking 200,000 cases. Do the math and look at what, 200,000 cases into 1 billion plus actually means in terms of the percentage of individuals who got infected during this time period from this particular parasite. That's important because what we in public health have to be careful not to do is make recommendations that are not based on necessarily good science and that are so overreaching that they end up causing a resentment from the general population. As I mentioned earlier, we see that with what happened with some of the issues around COVID.

Dr. Michael Osterholm: We've seen it in other examples where public health has been seen as being extreme and the overall good of eating over a billion meals of leafy greens a week, to me, outweighs the issue of contamination, as we have seen in this outbreak. So again, we need to respond to contamination quickly. We need to make sure that those products are off the market. And we want people to have healthy foods. And that combination, I think, is one, we have to have a really hard discussion about how do we communicate risk When the Michigan Department of Public Health put out a recommendation don't eat bagged lettuce and use head lettuce and cut it off this way. That was interpreted for the country to be their recommendation because no one else was speaking to it. That was a real mistake, because that did not match up with what we were actually seeing in the field. And the epidemiology curve that I just shared with you is one where also we had likely multiple outbreaks going on. And so the first outbreak, the outbreak that involved Taco Bell, was actually pretty much over by the time the public became aware that this outbreak was even happening. We were too late to pull the trigger and to get product off the market.

Dr. Michael Osterholm: There were some myths that came up during this time period. One was the fact that the CDC's budget was cut to eliminate surveillance for cyclospora in several different states. That's actually not true. The FoodNet program, which did eliminate cyclospora for surveillance, was not part of our national surveillance system, was meant to be a laboratory for additional investigation of parasites of other foodborne disease causing organisms. It was never meant to be a surveillance system. And in fact, 47 out of the 50 states in this country today actually have cyclosporiasis reportable. And those data are coming in. That was never cut. Now, CDC did take a big hit in staffing its parasite lab, which we really needed those laboratory support measures because they were going to help tell us what differences might exist between the different strains of cyclospora, which could help tell us, are these different outbreaks under the same outbreaks, just as we do for the same kind of tool used when we talk about bacteria outbreaks? So there were a number of issues where things went wrong and they still, to a certain degree, are wrong. But I'm hopeful that we can find a way to go back, carefully examine what went wrong and learn from it so it doesn't happen again.

Chris Dall: So Mike, bottom line here. Is it okay to eat lettuce?

Dr. Michael Osterholm: At this point? I would say absolutely. Given we have for so many states in this country, no additional activity would have had any previous year. And again, talking about the 150 million servings a day of this, to suddenly say, "Don't eat it," when in fact, this is an outbreak that is, I think, largely over. If you look at the epidemiological curve, we're really right now, I think, on the final throes of the entire outbreak, not to eat produce right now is really a waste of a very healthy food.

Chris Dall: Now to the ongoing Ebola outbreak in the Democratic Republic of Congo. Mike, what is the current status of the outbreak, and what did you make of a recent study in the New England Journal of Medicine that found currently licensed vaccines that target the Ebola Zaire virus might offer some protection against Bundibugyo virus?

Dr. Michael Osterholm: Unfortunately, the Bundibugyo virus outbreak continues unabated in the western DRC. Over the weekend, cases topped 3,200, including more than 1,400 deaths, in what officials are calling the fastest growing outbreak of Ebola on record. Contact tracing and containment of the outbreak have been incredibly difficult given funding problems. Attacks on health care centers. Population displacement from armed conflict and hazardous mining in the region, as well as mistrust in affected communities. Compounding the problem are health care workers strikes over unpaid salaries and bonuses, leaving patients without care. Earlier this month, health care workers at Bunia General Hospital in Ituri province, the outbreak epicenter, went on strike, and on Saturday, doctors, nurses and security staff walked out of a treatment center in Borneo. These staff are working without pay and perilous conditions, constantly at risk of infection. The WHO has said that more than 100 health care workers have contracted the virus since the outbreak began earlier this year. As you know, unlike the Zaire Ebola virus, there are no approved vaccines or treatments for the rare Bundibugyo virus, so researchers are racing to find ways to prevent and treat infections. In early July, scientists launched a randomized controlled trial in Ituri province to test two treatment candidates the antiviral drug remdesivir, that had been used to treat COVID-19, and the experimental antibody formulation MBP134. But it may take months and more than a thousand patients to determine if either drug is effective. In a promising development on Friday, a volunteer in the first phase one clinical trial of Bundibugyo virus vaccine, received the first dose of the University of Oxford's BDB vaccine. This vaccine was developed using the same technology as the Oxford AstraZeneca COVID-19 vaccine.

Dr. Michael Osterholm: In an incredible achievement, Oxford and the Serum Institute of India stockpiled 620,000 doses of the vaccine in two weeks, plus 4000 investigational doses for the trial. But again, it will take some time to determine the safety and effectiveness of the vaccine in a real world setting. Now, circling back to the New England Journal of Medicine study, you mentioned, Chris. The study looked at whether already licensed vaccines used against the more common Zaire Ebola virus could offer some protection against Bundibugyo. For the study, researchers took blood samples from 179 West African adults and children vaccinated with one of the two available vaccines from Merck to assess for antibody response against Bundibugyo. The sample showed some cross-reactive immunity, although it was about eight times lower than that against the Zaire virus. The two dose Ebola vaccine, produced by a subsidiary of Johnson and Johnson, elicited six times more antibodies for Zaire than Bundibugyo. The study authors said that the findings don't prove that the tested vaccines work against Bundibugyo, but urged the WHO to consider whether to deploy stockpiles in the absence of a licensed vaccine against Bundibugyo. Because the Merck vaccine is currently available through the global Ebola vaccine stockpile, it could be evaluated during the ongoing outbreak. As the authors note, public health officials rarely have perfect evidence responding to an infectious disease outbreak, such as Bundibugyo. Bottom line in short, this is an infectious disease tsunami that just continues to move, move and move. And unfortunately, we are watching all of our worst fears about what might happen, this outbreak actually come true.

Chris Dall: Let's turn now to measles. Last week, the CDC reported that 2,318 confirmed measles cases have been reported so far this year in the United States, surpassing the number of cases for all of 2025. And Mike, every time we see cases slowing down in one state like Utah, we see them picking up in another state like we're currently seeing in Pennsylvania. Is this just our new normal with measles?

Dr. Michael Osterholm: Chris, it's sad to say that I do think this may be our new normal. That is, until there's a major increase in vaccination, which isn't exactly a national priority at the moment. I also fear that things could actually get worse, as we saw with our neighbors to the north in Canada, where a year ago they had 4,500 cases of measles in a population of only 40 million people. I think that that could be our future. As you mentioned, we've officially surpassed last year's record breaking total, and there are still five months left to go in 2026. The U.S. has now reported more than 2300 cases of measles in 35 separate outbreaks. It's notable seven states right now account for 84% of the cases, and there's every reason to believe that more states will get added to this increased risk environment. Before last year, just remember, you had to go back 35 years to find this many annual measles cases. You're also right that the geographic location of these outbreaks is shifting. New cases are rising in Pennsylvania as well as Virginia and Florida. And while Utah seems to be slowing down, as you noted, I think their state epidemiologist, Doctor Alicia Nolan, has been making some very important points in her conversations with the press. First, she notes that the official case count, around 700 is certainly underestimating the true size of the outbreak. Remember that for many people, measles can be relatively mild, so there are likely cases flying under the radar. These cases still, however, are highly infectious. Researchers at the University of Utah estimate the actual number of infections could be 3 or 4 times higher than the reported total.

Dr. Michael Osterholm: The second point, brought up by Doctor Nolan, is that even if transmission slows down in one outbreak, that doesn't mean the state is no longer vulnerable. There are still many people who remain unvaccinated, and particularly in pockets of under-vaccinated individuals. Just to give a sense of scale, we can do some very rough math on the number of kindergartners in the state. In Utah, only about 88% of kindergarten students are up to date on their MMR vaccine. If there was roughly 60,005 year olds in Utah, that leaves 7,200 kindergarten students vulnerable. Now add on all their siblings, classmates, adults, everyone else in the community who is unvaccinated. And we still have a massive issue. And I might add, for those of us here in Minnesota, very proud of our public health tradition and our outstanding state health department. We are unfortunately in not much better shape than Utah. That's a sad commentary on public health today. It goes without saying that measles is a tremendous stress on health care and public health systems right now. Each measles case requires days of contact tracing, testing, vaccination efforts and follow up at a time when state and local health departments face staffing shortages and funding cuts. This is becoming a bigger and bigger issue. Additionally, isolation protocols for infected patients and health care centers further strain resources during a time of significant physician and nursing shortages. The solution to this problem is simple, but not easy. Higher vaccination coverage, strong primary care access, and well funded and functioning health departments. These are the investments that will make America healthy again.

Chris Dall: Mike, for the last few months, we've had nothing but good news to report about COVID-19. But according to the Your Local Epidemiologist website, it appears COVID-19 is now picking up in parts of the country. What can you tell us?

Dr. Michael Osterholm: It does seem like our quiet stretch might be coming to an end. We're seeing increases in SARS-CoV-2 wastewater concentrations, test positivity. Emergency department visits and hospitalizations. Before we dive into the specifics, I will say that across the board, COVID-19 levels are still very low. But the fact that we're seeing increases in each of these metrics at the same time is what is drawing our attention and the conclusions that activity is picking up. Overall, the national wastewater concentrations is still considered very low and levels remain very low in every region, though, we're starting to see concentrations increase in the west and northeast. Alaska is the only state with a moderate level of COVID-19 in wastewater, while California, Florida, Louisiana, Nevada, New Mexico, Texas and Washington are considered low. Officials in the Bay Area of California have recently warned residents of the increasing wastewater concentrations, encouraging residents to take extra precautions. Remember, the wastewater data is what we call a leading indicator, meaning it tips us off as to what we can expect to see in the coming days and weeks. It is also a helpful metric, as it does not rely on testing and reporting to provide data. Currently, we're also seeing increases in test positivity in emergency department visits that result in a COVID-19 diagnosis and hospitalizations. COVID-19 related ED visits are increasing in the youngest and oldest age groups those less than one year, 1 to 4 years and 65 and older. Hospitalizations are also increasing slightly, as is test positivity, although we don't put as much weight on what is occurring with test positivity because it can vary with a lot of factors.

Dr. Michael Osterholm: The CDC's variant tracking has not been updated since early July, but between the update and the traveler based surveillance, which is based on variants detected in samples from international travelers arriving in the US, there are not any new variants that are ringing alarm bells to me. Since early May, RF 0.5 and Omicron subvariant, first detected in Southeast Asia, has been the dominant variant, followed by Xfg. Again, there is nothing here that I am particularly concerned about. And while we're seeing signs of COVID-19 picking up, levels still remain very low. The timing of this increase is not ideal as we're approaching the upcoming school year, and the immunity from previous rounds of vaccine most likely have waned. But I still do not anticipate an Omicron like surge with these increases in activity. And let me add one last point with regard to COVID. We expect to see the updated vaccines available in your pharmacies and your doctor's offices sometime between mid-August and early September. So for those who have been at least six months out since your last dose of vaccine, or if you had a clinical illness in the last year, I would urge you to consider getting your vaccine again when these new vaccine doses become available. And last, before we move on, I have some good news to note about influenza and RSV. As you know, we always continue to monitor activity and will update you if there are any notable changes. But for now, his status quo.

Chris Dall: Finally, I want to follow up on West Nile Virus, which we discussed in our last episode on summertime infectious disease threats. Mike, are you seeing any unusual activity this summer?

Dr. Michael Osterholm: Well, Chris Peak West Nile virus transmission in the United States usually occurs in late August or early September. However, the CDC has already announced an unusual early surge in West Nile virus activity. As of July 21st, when CDC's website was last updated, there have now been 91 reported cases from 20 states in 2026. However, approximately 80% of West Nile cases have no symptoms or mild symptoms, so keep in mind that the true number of cases is likely much higher. Over half of all the reported cases this year have occurred in Arizona and are. Most are concentrated in the Phoenix Valley. Since Culex mosquitoes breed in standing water, you wouldn't necessarily think that the desert would be a high risk area for West Nile. But that's not the case. And in fact, even in a desert area, the following water bodies provide ideal breeding grounds for Culex. Leading the list in the Phoenix area alone are neglected swimming pools where the mosquitoes breed with lots of leaf litter or swimming pools have not been cleaned out. Storm drains and catch basins where water that might run off your lawn from when you're doing watering creates a wonderful environment just below the level of the screen grade on the road. Other water features such as ornamental ponds, even evaporative coolers where water ponds can provide an ideal location for growing. And so in a sense, every place is at risk for West Nile. Some were open bodies of water, such as in the Midwest. In the east, where there is more water available that surely can lead to increased propagation of the Culex mosquito.

Dr. Michael Osterholm: Among the 91 reported cases in the United States, 64 were in what we call neuroinvasive. However, from what we know about West Nile epidemiology, only 1% of cases result in neurologic symptoms, which is another reason I think the true number of cases is much higher than reported. There are a few groups of people at high risk for severe illness with West Nile, including those over the age of 60, those with a weakened immune system and those with underlying medical conditions including cancer, diabetes, hypertension and kidney disease. The good news is that West Nile is very preventable. There are many things our listeners can do to prevent West Nile, as well as other mosquito borne viruses. Make sure that you eliminate any standing water on your property, even birdbaths, which may seem like a great idea for the birds, can be a real problem in terms of propagating mosquitoes. Another way to reduce the risk deals with mosquito repellents. These repellents should be an EPA registered insect repellent containing Deet. When possible, wear long sleeves, pants and socks when outdoors. This will also go a long way for preventing tick bites. And then finally, those really at highest risk for having serious illness should avoid being outdoors during dawn and dusk when the mosquitoes bite the most. We will keep our listeners informed of any new updates for summertime infectious disease threats as the season progresses. For now, the mosquitoes and ticks are still high on our list.

Chris Dall: Now it's time for our favorite segment this week in public health history. Mike, what are we commemorating this week?

Dr. Michael Osterholm: Well, you know, I love hearing you say that about a favorite part of this podcast because I think many of us agree this really is one. And it's one that I learned a lot from. Today, I want to celebrate the 61st anniversary of Medicare and Medicaid. On July 30th, 1965, President Lyndon Baines Johnson signed Medicare and Medicaid into law. These two national programs were known as the Social Security Amendments of 1965. Medicare established health insurance for most Americans 65 and older, while Medicaid offered insurance for low income adults under 65. The move was motivated in part by a very important research from Dorothy Rice, a government economist and statistician. In 1964, Rice published a landmark study on Asian American rice study highlighted how about half of those 65 and older had no health insurance, and that those who needed it most were the least likely to be able to afford it. Additionally, many private health companies didn't want to cover this population due to their age and chronic condition, leaving many elderly people dependent on their children for care. Because of Dorothy's research, people better understood the needs of the Medicare population, which motivated support.

Dr. Michael Osterholm: The call for a national health insurance was actually proposed 20 years earlier by president Harry Truman following World War Two. However, his effort failed to gain traction at the time. To honor this, President Johnson signed the Medicare and Medicaid Act, sitting next to former President Truman. Truman was even enrolled as the first Medicare beneficiary. Once the law passed, the administration enrolled over 19 million Americans in a matter of months. In the years since, these programs have expanded to cover more people, including the permanently disabled, low income pregnant people, and children of low income families. Without a doubt, Medicare and Medicaid have helped millions of Americans have access to medical care that they wouldn't have otherwise received, and have contributed to many critical public health improvements over the last 60 years, from reduced infant and maternal mortality to improved care for chronic conditions like high blood pressure and diabetes. Life expectancy in the U.S. has increased nearly nine years in the past 61 years, and I have no doubt that Medicare and Medicaid have helped play a significant role in this wonderful accomplishment.

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

Dr. Michael Osterholm: Well, Chris, let me give you those top three again. As I noted, the outbreaks of Cyclosporiasis were experiencing here in the United States are terribly unfortunate in many regards. It's been a food safety failure, a lack of government leadership. And it means we caused an important source of healthy food to be abandoned. Second of all, Ebola is still that infectious disease tsunami I talked about months ago. And nothing seems to be changing that unless we have some major medical breakthrough, like a vaccine that can be used among the population, I fear that this outbreak is going to continue to burn and burn and burn. And then finally, the last one is COVID may be on the rise. I think we have to be very careful here in assuming that that's going to happen around the country. But what's happening on the West Coast makes me believe that we're within several months of possibly seeing much more widespread transmission in the population. Now, remember again, as I noted before, we expect to see releases for the new updated COVID vaccine by late August and early September. And I would surely avail yourself to those vaccines.

Chris Dall: And Mike, what is your closing for this episode?

Dr. Michael Osterholm: Today, I'm going to be sharing words with you from someone who really needs no introduction. Rachel Carson. Rachel was an American marine biologist, writer, and conservationist who c trilogy in 1941 to 1955, and her book "Silent Spring" in 1962, are credited with advancing marine conservation and the global environmental movement. And specifically today, I'd like to share with you one of, I believe, Rachel Carson's most notable pieces. First published over a half century ago, Rachel Carson's award winning "A Sense of Wonder" remains a classic guide to introducing children to the marvels of nature. In 1955, as the author of Silent Spring, she began work on an essay that she would come to consider one of her life's most important projects. Her grand nephew, Roger Christie, had visited Carson that summer at her cottage in Maine, and together they had wandered the surrounding woods and tide pools, teaching Roger about the natural wonders around them. Carson began to see them anew herself, and wanted to relate that same magical feeling to those who might help to introduce a child to the beauty of nature. Let me share one quote with you from the book, because I think it really links back to our dedication, talking about what's happening with our forests and the firefighters who are doing their best to help us all survive within those fiery environments, Carson wrote:

Dr. Michael Osterholm: "And I share those who dwell as scientists or laymen. Among the beauties and mysteries of the earth are never alone or weary of life, whatever the vexations or concerns of their personal lives. Their thoughts can find paths that lead to inner contentment and to renewed excitement in living. Those who contemplate the beauty of the earth find reserves of strength that will endure as long as life lasts. There is symbolic as well as actual beauty in the migration of the birds, the ebb and flow of the tides and the folded bud ready for the spring. There is something infinitely healing in the repeated refrains of nature. The assurance that dawn comes after night and spring after the winter." Rachel Carson.

Thank you all for joining us again this week. I hope that we're able to provide you with some of the information you're looking for. Again, we always welcome your feedback at this crazy, crazy time in life with everything that's happening in our world. Sometimes it feels impossible to make sense of it. And when you can't make sense of it, still doesn't mean you can't be kind. And now, more than ever, is the time to be kind. So I hope we all take that away this week. Be kind. Share that kindness. Thank you.

Chris Dall: Thanks for listening to the latest episode of the Osterholm update. If you enjoyed 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.um.edu. This podcast is supported in part by you, our listeners. The Osterholm Update is produced by Sydney Redepenning, Elise Holmes and Ruby Guthrie. Our researchers are Cory Anderson, Meredith Arpey, Leah Moat, Emily Smith, Clare Stoddart, Angela Ulrich and Mary VanBeusekom.