Health: Searching For The Source Of Cyclospora

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0:37you may have heard of a parasite that's causing some gastrointestinal distress here's what people are saying online i have the parasite that's going around cyclospora yes the explosive diarrhea parasite i have been victimized by cyclosporiasis i think that's how you say it I started having severe nausea, vomiting, and explosive diarrhea at the same time. And then I had fatigue. I had chills. I had sweats. I had a low-grade fever. And I had severe abdominal pain. My stomach hurts. It's like cramping. It feels like someone is squeezing your insides or punching you from the inside out and trying to get out.

1:17It hurts so badly. I've had it for about four days now. I have lost weight, so that's nice. Like, appetite gone. Today I had one meal immediately came out of me. Like, we're talking within 10 minutes. The parasite cyclospora has sickened thousands of people across 34 states this summer. That's more than six times the number reported at this point last year. The CDC has linked a major cluster to shredded iceberg lettuce at Taco Bell in some states. And Taylor Farms de Mexico has now pulled all of its iceberg lettuce from the U.S. market. But with an outbreak this large, experts say there's likely to be more than one source.

1:53I'm Naila Boodoo, in for Jen White. You're listening to the 1A Podcast. Today, we're here to answer your questions and ours, what cyclosporiasis is, how you get it, and why investigators have had such a hard time finding the source. Later in the show, you'll also hear from Michigan's chief medical executive about how the state with the largest number of cases is coping so far. So stay with us. We'll be right back after this short break.

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2:58Planet Money Summer School. Grab some friends, pack your bags, and don't forget the sunscreen. Listen on the NPR app or wherever you get your podcasts. Welcome back to the 1A Podcast. We're talking about cyclospora and what's being done to manage and treat the spread of the parasite. Joining us from Bellingham, Washington, is journalist Halina Bademiller-Evich. She's founder and editor-in-chief of Food Fix, an online publication about food policy. She's covered many foodborne illnesses and outbreaks over the course of her career. Halina, welcome. Thanks for having me. And Caitlin Rivers joins us from Baltimore.

3:33She's an epidemiologist and directs the Center for Outbreak Response Innovation at Johns Hopkins University. She's the author of the book Crisis Averted, The Hidden Science of Fighting Outbreaks. Her work focuses on how outbreaks are detected, investigated, and contained. Caitlin, thank you for joining us as well. Great to be with you. Caitlin, can we start with the basics? What is cyclosporiasis and how do you get it? Cyclosporiasis is a parasitic infection. You become infected by consuming contaminated food or water. Often in the United States, previous outbreaks have been linked to imported fresh produce.

4:11And so that's why we've been hearing a lot about whether the source is iceberg lettuce or what investigators are looking for. Cyclosporiasis causes weeks of relapsing diarrhea. So you may get better and then you get worse again. You get better and you get worse again. And it's a very unpleasant illness. Helena, we got this email from Peggy in Michigan who says, early reporting said that cyclospora is not transmitted person to person. This item has disappeared in current reporting. Can you please clarify? Yeah, this is a great question. I think one of the really hard things about cyclospora is just how little we know about it in the U.S.

4:47It has, as was just mentioned, mostly been something we've thought about with imported food or traveling abroad. And so we have a real dearth of research in the U.S. There's only a handful of researchers. We do not think that it spreads person to person. It's mostly through human feces or, as was just mentioned, contaminated water, contaminated food. But we're also now seeing some reports of people getting this infection at pools or splash pads because chlorine does not easily kill the parasite. And so I think we need a lot more research. Right now, though, the biggest concern is certainly contaminated food and water.

5:27Caitlin, a member of the 1A Text Club wrote, what is the difference between this cyclospora parasite and other intestinal parasites? There are multiple different kinds of parasites that you can get from contaminated food and water. Cyclospora is moderately common in the United States. We record about 3 ,000 to 4 ,000 cases on average. It is treatable with antibiotics, whereas some other parasitic infections are treatable with anti-parasite medications. So there are a few differences, but there's a lot of similarities. The diarrhea, the weight loss, the abdominal discomfort. So again, a very unpleasant illness and certainly one worth avoiding.

6:08How is it different from food poisoning? I think people are much more familiar with foodborne illnesses like salmonella or E. coli. Well, cyclosporiasis does not transmit person to person, and it does not necessarily come from shared food that was left out too long. That's a big distinction. When we think about cyclosporiasis outbreaks, we think about imported fresh foods, whereas a salmonella or an E. coli outbreak is more often associated with poor food handling practices. For example, if you leave a meal out on the counter too long, it allows the bacteria to replicate. Or if a food handler doesn't wash their hands.

6:45The consequence of that difference is that the more traditional, if you will, foodborne outbreaks are smaller in scope because there's only so many people who can be affected by a dish that was left on the counter too long. Whereas with this cyclosporiasis outbreak, when we're thinking about imported foods that have gone to as many as 27 states, we're looking at a much bigger footprint. Caitlin, there are cases of cyclosporiasis, as you've noted, every year in the U.S. When did this outbreak start to get attention from folks? The data that reflects the number of cyclosporiasis cases reported in the United States started to increase in May, which is typical.

7:21The standard season is May to August. And so I think we're still learning when the outbreak began relative to when the traditional season started. But certainly by late June, early July, public health officials were confident that there was an outbreak underway. And so we're now at least three, four weeks into this outbreak and still learning new things every day. Helena, the FDA announced Taylor Farms is volunteering recalling all iceberg lettuce shipped from central Mexico to the U.S. The lettuce was linked to cyclosporiasis cases traced to Taco Bell locations in five states. What do we need to know about the recall first?

7:58Yeah, so the recall is for iceberg lettuce that is from central Mexico from Taylor to Mexico. So most of this lettuce went to food service, not retail. So it went to places like restaurants and hospitals, Taco Bell, as you mentioned. There was some iceberg lettuce that was recalled from Walmart under the MarketSide brand name. Consumers can go. You can just Google FDA iceberg lettuce recall and you can get all of the details. That product should be discarded. You can go back to your retailer and get a refund. If you have symptoms, you should talk to your doctor. But right now, it appears that this particular cluster that they have identified, which is across five states and thousands of cases, is likely linked to this lettuce that was imported from Mexico.

8:51FDA officials have been very careful to note, however, that there are multiple outbreaks under investigation. And as was just mentioned, we have a cyclosporus season now in the US. This is an emerging issue. And so there are likely multiple clusters going on caused by multiple things, which has added a lot of confusion, understandably, for consumers during this time. Helena, why can you explain a little bit about the cyclosporiasis season and what's driving that longer-term trend of rising cases in the U.S.? Yeah, I think this is one of the things that has really been underreported, underexplained during this current situation.

9:32Unfortunately, over about the past decade, we have seen a rise in cyclospora cases every summer. We've been seeing sort of a slow uptick in the number of sort of natural increase in cases we've had in the U.S. every summer between usually May and August. Also, there's always been some level of travel where people travel to another country and they get cyclospora and then they come home and it's diagnosed. But we're seeing increasingly domestically acquired cases, many times from imported fresh produce. But we've also seen some outbreaks tied to domestic produce from California and even Florida.

10:15And so there is some concern that this might be driven by changes in the climate. A warming climate can change where different bugs thrive and take hold. And so there's a lot we still don't know about this parasite, but there are some concerns that we're seeing a general trend change. And some of that may be driven by climate change. Caitlin, can I ask you about testing? we've heard from the FDA that a positive cyclospora test of lettuce from Taylor Farms de Mexico was actually a false positive, but that the lettuce is still being recalled. Why is cyclospora particularly difficult to trace compared to other foodborne pathogens?

11:00Yeah, because it's a parasite, it can't be cultured. And so it's hard to get an adequate sample to really get a close look at the bug. It's also not present in every component of the food item. So you could have a bag of lettuce, if you will, and test part of it and the other part doesn't have the contaminant, but it is nonetheless a contaminated product. That is making it difficult to diagnose or to take a closer look actually at the food items that are under investigation. But we also see difficulties in diagnosis at the patient level. So cyclospora is not on the standard panels that a doctor may run for a patient who has diarrhea.

11:39It has to be specially requested. And so the fact that this is a parasite and a fairly uncommon one at that is introducing multiple challenges into finding the edges of the outbreak and tracing it back to its source. Coming up, we hear from Michigan's chief medical executive about what it's like to be at the epicenter of an outbreak of this scale and what the investigation actually looks like on the ground. Stay with us.

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13:16Welcome back. Michigan is at the center of a cyclospora outbreak and the numbers there are staggering. the state has reported more than 6 ,000 cases of cyclosporiasis. In a typical year, Michigan sees about 50 cases. More than 100 people say they were hospitalized. Here with us to talk about it is Dr. Natasha Bagdasarian, Michigan's chief medical executive and a member of Governor Gretchen Whitmer's cabinet. Dr. Bagdasarian, welcome. Thanks for having me on. We're also continuing to hear from you. A member of the 1A Text Club writes that he thinks he has cyclosporiasis. It's been almost a week.

13:50Time for doctor's help. I'm using Imodium, adult Pedialyte, eating bland foods, avoiding veggies and fruit. I've lost over three pounds. I've never had a fever, but I have the other symptoms. Not fun. Calling out for work has not been an option. This has been brutal. Dr. Bagdasarian, you now have more than 6 ,000 laboratory-confirmed cases. When did you first realize something was out of the ordinary? What did the early days of your investigation look like? Well, we saw a really strong signal that something was happening around early July. So July 1st was our first press release that there was something going on.

14:26The cases that were reported to us were folks who started experiencing symptoms towards the end of June. And we've now had sort of two peaks when we look at our data of cyclosporiasis here in Michigan. The first one occurring at the end of June and the next one happening in early July. How does this work? Like, how does tracing work? Your team has conducted 2 ,700 interviews so far. Who's doing those interviews? What do they look like? Well, as of today, we actually have over 6 ,500 cases of cyclosporiasis, and we've completed almost 3 ,000 interviews. So we're working with our local health departments.

15:09We are bringing people in from all kinds of different work projects and different work streams who are contacting each one of those individuals with cyclosporiasis and doing a detailed interview on the foods that they consumed in the two weeks prior to their symptoms starting. Now, by the time they've tested positive for cyclospora, by the time that test has come back positive and we've heard about them, it means that their actual exposure to contaminated food could have been four weeks ago. So they're having to recall what they ate, where they went to eat, where they purchase their groceries from several weeks before the interview takes place.

15:48And each one of these interviews takes about 45 minutes to conduct. So that's a lot of manpower that the state of Michigan is devoting to this. Is it also, it sounds like local, you're having municipalities also involved in this? Well, our local health departments are definitely part of this response, a huge part of this response. Our cases of cyclosporiasis have spanned across 68 Michigan counties. So each one of those local health departments is also doing a proportion of these interviews. So they are pulling staff from all kinds of different areas, as are we here at the state level. Dr. Bagdasarian, how did you come to identify then Taco Bell and bagged lettuce?

16:28Was it through these interviews? So through the interviews, I can tell you what our data is showing. You know, we are able to cross-check all of this data and look for signals. And by far, the strongest signal that we are seeing is exposure to lettuce. We have to remember that not everybody recalls what food they ate. And also, there is background noise as well. People eat all kinds of different things in their day-to-day lives, especially over a period of two weeks. But about three quarters of our cases report that they definitely had exposure to lettuce. Now, the type of lettuce varied. There are folks who said they had exposure to pre-made salad, romaine, iceberg.

17:11Some of them bought lettuce in grocery stores. Some of them consumed lettuce at restaurants. But lettuce has definitely been our biggest signal. And that's why we issued specific recommendations on how to consume lettuce right now in Michigan in order to reduce your risk of cyclosporiasis. Now, I also have to say that there is a proportion of patients here, about 12 % of patients, who don't recall specific exposure to lettuce or eating at a specific fast food chain. So there could be two things going on here. So, right, I was going to ask if you have leads on other potential outbreak sources, do you believe there could possibly be other outbreak sources then?

17:56It's very possible. You know, if you look at national coverage, there are a number of states that are experiencing higher than normal numbers of cyclosporiasis. In New York recently, there was an outbreak of cyclosporiasis linked to cilantro. Other states are seeing, you know, different patterns and different trends emerge. And what we really need is our federal partners at the CDC to compile all of this data and provide a holistic look across states. And of course, we need our colleagues at the FDA to do that traceback so they can find the specific item or items that have been contaminated. We're speaking with Dr.

18:35Natasha Bagdasarian. She's Michigan's chief medical executive. Dr. Bagdasarian, are you getting the support you need from the CDC and the FDA? Well, I'll tell you, I think people are doing the best they can under a really demanding situation, just as we are here in our state. And what I can tell you is, and everyone knows that there have been cuts to public health over the last year. There have been cuts to the CDC, and a lot of that federal money is money that normally flows down to states and to local health departments. And based on that federal money alone, here in the state of Michigan, we have lost 23 staff in our Bureau of Infectious Diseases.

19:17We've lost one entire regional laboratory. Our local health departments have lost 123 staff. And as you know, those same cuts have been seen at the federal level in the CDC. So people are understaffed, they're overworked, they're stretch really thin. And we're doing this work while Michigan is experiencing unprecedented heat waves, unprecedented air quality. We're seeing a rise in communicable diseases, vaccine-preventable diseases like measles, mumps, pertussis. And so public health is being stretched in ways it's never been stretched before. Can I ask what your message is then to people as they think about funding for public health, what you want people to know?

20:01Well, you know, I think for a lot of folks, they didn't really understand what it was that public health did. They didn't really understand the benefit to themselves, to their communities, their families. And then after COVID, people really associated public health with masking and vaccines and things that have become increasingly politicized. And I do want people to recognize that food safety is an integral part of the work that public health does. And if folks care about their food safety, if people think that 6 ,500 cases of a parasitic diarrheal disease in Michigan alone is unacceptable, then it's important that we fund at the national level, at the federal level, the infrastructure we need to prevent disease outbreaks like this from happening in the future.

20:50Dr. Bagdasarian, do you expect that cases will level off now that we've seen the recall from Taylor Farms in particular? You know, I think that every recall is going to be helpful. However, I do have to say that we still are interviewing folks here who are not reporting exposure to iceberg lettuce. And we also know that people are reporting exposure to lettuce and produce at places other than just restaurant fast food chains. And so my concern is that the outbreak is bigger than the current recall covers. And we need our colleagues at the FDA to continue their traceback work and to make sure that we've identified any and all contaminated produce.

21:38I do think we've been issuing a lot of guidance about the safest ways to eat produce. We put out guidance on July 1st, July 4th, and I am hopeful that as people start taking those recommendations, as they start buying whole heads of lettuce versus bagged salad mixes, for example, that we start seeing a slowdown in some of these cases. Dr. Bagdasarian, there's, of course, a lot of internet speculation around this outbreak. What can people do to help the investigation? Well, you know, if you, number one, if you're having symptoms, if you're having watery diarrhea that is prolonged, that's not getting better, or it gets better and then comes back, and you live in a place like Michigan, it's important to seek medical care and to specifically asked to be tested for cyclospora.

22:27Not all stool tests will cover this particular parasite, so it's important to get tested. Those test results automatically come to the state of Michigan, and we're conducting our investigation, and you will likely get a call from someone asking you about your food history. And a lot of folks don't want to answer those calls or don't want to have a 45-minute interview with public health, but those interviews are really helpful in providing us with clues. So I would encourage people to get tested if you're symptomatic, get treated, of course, and then please, please cooperate with public health when we do reach out to you.

23:05That's Dr. Natasha Bagdasarian, Michigan's Chief Medical Executive, a member of Governor Gretchen Whitmer's cabinet. Dr. Bagdasarian, thank you for your time. We appreciate it. Thanks for having me on. Epidemiologist Caitlin Rivers is still with us. She's the author of Crisis Averted, The Hidden Science of Fighting Outbreaks, and journalist Helena Bademiller-Evich, founder and editor-in-chief of Food Fix, an online publication about food policy. Caitlin, can I just ask you to sort of follow up on what Dr. Bagdasarian was saying about the contact tracing, about the state of the public health system, particularly as we look at those cuts?

23:42I'm just curious your response to what she was describing to everybody. I think what we heard from Dr. Bagdasarian is dead on and exactly what I'm hearing from my colleagues across the industry. There have been cuts after cuts after cuts to public health capacities. And it sounds like an abstract concept. You know, we're talking millions of dollars. And as an everyday person, it's difficult to understand what that means in practice. But what it means is that we are more likely to face outbreaks like the current one that we are facing. And when something does pop up, our public health officials are under enormous strain to respond effectively.

24:18We see that really at all levels, the federal level, the state level, the local level. We see it across FDA, across CDC, really far-reaching consequences. And I do fear or worry that we're going to continue to see outbreaks that are difficult to manage because of these very real and consequential cuts. Helena, we're getting quite a few questions about the idea of testing and particularly the technology used to determine whether or not you have the parasite. We got a message from Will in Maryland who said, Many other microorganisms can be quickly and reliably detected in lab specimens using methods based on DNA sequences specific to each particular pathogen.

25:01What is the difficulty in using PCR technology in DNA sequence recognition for cyclospora diagnosis? Helena, can I ask you to answer that? Yeah, it's a really good question. As I mentioned earlier, we still have a lot of scientific gaps about this particular parasite, and it is a tricky one to begin with. The long incubation time makes it really hard to track down what food might be causing it, and then it's really hard to deal with in a lab. So not only trying to find it in lettuce is difficult, but then you can't grow it out to take a genetic fingerprint of that parasite and then match it with other cases, which is what investigators are able to do with pathogens like E.