Cyclospora (and other diarrhea-inducing parasites)

24:15In this case, it seems like the lettuce came from Taylor Farms de Mexico. My Spanish is really good, everybody. And so they probably need to be held to the same standards as U.S.-based producers. And Taylor Farms should be sending people to go check out what's happening from time to time. But it looked like something fell apart. And so another step that happens here that's sort of in between what we've talked about so far is that if it turns out that you think, for example, it's lettuce from Taco Bell, then you say, okay, Taco Bell, where did you get your lettuce from? You're supposed to be keeping careful records.

24:52And so they'll tell you, all right, we got it from Taylor Farms. And so then you'll say, all right, Taylor Farms, which bags of lettuce did you send to Taco Bell? And where did the lettuce in each of those bags come from? And they're supposed to be keeping super detailed records so that they can tell you exactly which farm the lettuce came from. And that could change over time. Sounds like a good plan. Sounds like a good plan. Right. And then you have to go and actually visit those farms and try to find it. But again, these symptoms could be showing up weeks after. And so a lot in a lot of cases, you're not going to find the smoking gun because the lettuce has expired.

25:26It's been thrown out. It's in the trash. You can't necessarily find those connections anymore. So for the outbreak we're having right now, it appears that what happened is that they've tracked it back to a particular farm. They haven't been able yet to get a positive sample where they say, definitely we found cyclospora at Taylor Farms, De Mexico's farm, and it matches with what's in the gut of somebody up in Michigan. But they have been able to say that pretty much everybody who has had cyclospora, all of the evidence that we have suggests that it routed through Taco Bell, through their lettuce, to Taylor Farms lettuce that came from Mexico.

26:05All right. So let's take a break because I need a break. So much poop on the brain. And when we come back, we'll dig into the various critters that can give you diarrhea.

26:44We'll be right back. Watch live Saturday on CBS at 12 p.m. Eastern, 9 a.m. Pacific, and catch replays Monday on BET. Presented by iHeart. A yay yay?

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29:07Okay, we're back and we're talking about our feces-covered world. We like to think we live in a world that's mostly clean and sparkling. But in reality, there's poop everywhere, isn't there, Kelly? There's poop everywhere. Almost everywhere. And in the United States, about a million people each year get infected by the first parasite we're going to talk about, which is Giardia. Daniel, do you want to guess when Giardia was seen for the first time? The first time it was ever seen, like in human history? Yeah. Oh boy, I'm guessing. Like with the human eye. Oh, with the human eye. I'm guessing the first cases of Giardia are probably like Babylon.

29:46Probably, yeah. But if Giardia is very small, it probably required the invention of the microscope. So I'm guessing a couple hundred years ago? Yeah, something like that. But do you want to guess who? Who looked at almost everything that came out of him and reported back to the Royal Society? is it what's his name van lewin hook yes yes he had diarrhea he put it under the microscope and he saw giardia and was like oh hello historical diarrhea amazing yep historical diarrhea anyway all right is there a museum somewhere that has like a sample of his original diarrhea that changed the world sure hope not definitely doubt it and it didn't change the world because he didn't make the connection between what he was seeing in his poop and the cause of the Giardia.

30:32Because, you know, there's a museum for almost everything. Like, I've been to Iceland. I've been to the Phallic Museum. I've read about that. It's amazing. Yeah. Yes. I have a picture of my kids standing next to a blue whale phallus. It's impressive. Nice. The bone, right? Yes, exactly. So I imagine somewhere there's a museum of diarrhea. You know, I got to be honest, I wouldn't be opposed to that as a museum idea, because I feel like, you know, diarrhea has taken away many people throughout history, you know, whether it was cholera or like dysentery during wars. And so I feel like you could have a pretty interesting human history story told through the Museum of Diarrhea.

31:11And like one of the greatest human victories, in my opinion, ever is like our amazing sewage systems. And so I would go to that museum, Daniel. Okay. Sign me up. So tell us about Van Leeuwenhoek's diarrhea. Oh, well, that's all I had to say on the topic of Van Leeuwenhoek's diarrhea. But Giardia is unique amongst the diarrheal parasites, and that is the only one where the descriptions of symptoms include really awful farts and stinky, greasy, floating poops. And I got to tell you, I spent a lot of time trying to figure out what it was about Giardia in particular that resulted in stinky, greasy, floating poops as opposed to the other kinds of poops.

31:51I couldn't get to the bottom of it, Daniel. I spent hours and I could not get to the bottom of it. You mean like people don't know or you couldn't find the answer? So when I was looking up how does Giardia cause diarrhea, I found this quote. The mechanisms by which giardia causes diarrhea and intestinal malabsorption are probably multifactorial and not yet fully elucidated. We don't know. Wow. But what we do know is that when it gets into your intestines, it has this disc. And it uses the disc to stick to the little finger-like projections that go out into your stomach across which things are absorbed.

32:31These are called villi. and it sticks to the villi and it causes them to flatten and start sticking together. And so the surface that you used to use to like absorb stuff into your body now have much less surface area because they're like smooshed and touching each other. And that makes it harder for your body to absorb the food and the water that you drink. So presumably more of it just passes right through. But again, the connection between knowing that it's like messing up the villi and the exact reason why you get this particular kind of diarrhea is something I don't think that we know yet.

33:06And when you say it causes stinky poops, like all poops are stinky. So is this like especially stinky or like stinky in a weirdly Giardia fashion? Like could a Giardia specialist smell a poop and be like, oh yeah, that's Giardia? I think yes. Right. So I had a roommate who went to Guyana to go visit her girlfriend. And when she came back, first, she got dumped, but second, she got Giardia. And so it was like a particularly bad trip for her. But she complained that like her poop smelled so weird. Like, wait, you know, we've all had diarrhea at some point in our life. Right. But this was different.

33:46And I fortunately didn't live with her at this point. I moved in with her later. But but anyway, so so yeah, I think it's it's a unique odor, apparently. All right. So we know these things are attaching to the lining of the stomach and that obviously is going to affect your digestion. We don't understand exactly why it causes weird poops or diarrhea or whatever, but what's the whole life cycle? Why are they attaching to the lining of our stomach? How does that benefit them? Yeah. So the way that you get it is you ingest a cyst stage that's in the water and it can be put in the water by other people who pooped in the water.

34:20It can be put in the water by beavers. Beavers are pretty common. carriers of this parasite. And so they're doing their little beaver thing. They poop in the water and then you think, oh, it's so pristine out here. I'm going to take a drink without first boiling and or filtering my water. You know, I had no reason to dislike beavers until today. I was just 100 % pro beaver. And now I'm like, wow, there's something in the negative column for beavers. They poop in the water. I'm still 100 % pro beaver, man. Like our poop probably gets in the water sometimes too. Like don't, it's not their fault.

34:50It's Giardia's fault. I'm not saying it swung me all the way to anti-beaver. I'm saying now there is something in the negative column, whereas it used to be just everything was good about beavers. Okay. All right. Well, you do you. I still like beavers. We have a couple families of beavers on our property. What? Yeah. I actually saw one of their dams, the recent monsoon-style rains we got here in Virginia in the middle of our giant flood washed out their dam, which was – I see. I hope they're rebuilding. And don't you drink well water? Is that potentially contaminated by beaver poop? Yes. Yeah.

35:25So you do have to worry about that. If you live in like a wildernessy kind of area, you have to be careful. We do check our water once a year. Oh. But I am more concerned with the proximity between my septic field and my well water, which is still like more than sufficiently far away up to code or whatever. But yes, when you live out in an area like I do, you do need to get your water tested regularly to see if human feces or animal feces have managed to get in. Wow. But anyway, so you accidentally consume it. It passes through the stomach and when it gets to the intestine, it breaks out of the cyst.

35:59Okay. Yeah, so it's got to get through the stomach first. I don't know why it's the intestines in particular that are the best place for it to live, but because it needs to produce cysts that go back into the environment, attaching to the intestines, replicating like crazy, producing more cysts and inducing diarrhea seems like a pretty good way to get your babies back out into the environment. But why do you need to induce diarrhea? I mean, you're in the intestines. You produce more cysts. They can just go in the normal poop, right? Why do you have to interfere? Why do you have to cause cramps that make everybody so miserable?

36:31Well, I can imagine diarrhea being more likely to get washed into a waterway or get like, maybe you are walking along a river. And if you need to have your normal bowel movement, you'll be like, I can make it home. But if you've got diarrhea, you're not making it home. And so it just happens where it happens. And I think for some of these things, it's tempting to look for evolutionary reasons. And I can imagine that - I'm sorry, I'm still stuck on diarrhea colon. It happens where it happens. Right. Maybe that should be the title of this episode. Or like a t-shirt or something. Yeah, something like that.

37:08Something uplifting. But anyway, so that's the life cycle. All right. If you go to the vet, you might hear that your dog or cat has giardia. That doesn't necessarily mean that you need to worry. The dog and cat versions don't usually jump to people. But you should always wash your hands after dealing with animal waste. And, you know, don't let your dogs put their butts on your pillows. This is like one of the things where I feel like I go to loads of houses and people's dogs are up on their beds with their butts on their pillows. And I'm like, friends, no, your face goes there later. Well, also, a lot of people kiss their dogs or let their dogs lick their faces.

37:46And I'm like, have you seen where your dog's face has been? Because it's been up its own butt or its neighbor's butt. And so, yeah, people should think about that. They should. Yes. I'm going on the record. But in terms of giardia, you get it in you, you get diarrhea. Does it naturally just progress? Does your immune system eventually tackle these things? Or do you just have giardia forever unless you take some antiparasitic medicines? Yeah, so some people are asymptomatic and will have it for a long time. Some people get really bad symptoms and we do have medication that you can give them to treat it.

38:19And in some people it will go away on its own. But again, I am not a medical doctor. So if you think you have Giardia, let your doctor tell you if you should see if it goes away on its own or if you should be taking some medication for that. S***. Sorry. Thanks for bleeping that, Matt. And look, I included a photo because Giardia, if you are a parasitologist, we tend to think of Giardia as one of the more charismatic looking parasites. What? Do you see the picture? Yes. So it has two nuclei that look like eyes. in the picture that I sent you, it doesn't have, there's like another organelle that kind of looks like a smiling mouth.

38:55It's missing in this artist's rendition. And it also has multiple pairs of flagella, which are long like hair-like things that it uses to help it move around. And they kind of like, it makes it look like they've got a little bit of hair on top of their head. Like they've got like a sort of wavy mustache that comes down. No, no, I'm not seeing it now. There's no charisma to this thing. Oh, you are a hundred percent wrong. The number of my friends who have jewelry with Giardia on it is, there's a lot of us. This thing which causes human suffering and death, you guys are celebrating and elevating to the level of jewelry.

39:31Cool. All right, let's talk about death. So for all of the parasites that we're talking about today, if you are immunocompetent, so you're not having immune system issues, so you don't have HIV AIDS, you haven't recently had an organ transplant. You know, there's a long list. You're not being treated for cancer or anything like that. Most of these parasites aren't going to kill you. And there's treatments for them. And you will feel unpleasant. But especially if you're in a developed country, we can get it under control. The folks where we need to worry are people who are immunocompromised. And in some cases, we don't have good medications to help people who are immunocompromised when they get infected by these parasites.

40:10And so, yes, I know every time we talk about parasites, you sort of squash my enthusiasm for the topic by talking about all the people who are suffering. I care about the people who are suffering, but I can also have immense respect for parasites that manage to eke out a living in such a, like, complex and efficient way. I mean, I think it's fair. You asked me if I worry about the suffering of protons at the large area of the water. And you said no. And then we moved on. And then you said you've killed billions of them probably that have been around for billions of years. And you ended what could have been an infinite lifespan.

40:47That's true. Yes. But protons don't cause diarrhea, Kelly. All right. I guess, you know, protons assembled in the form of Giardia do. So that's right. Yeah. Right. Right. Your protons cause suffering. Interesting philosophical question there. Who's to blame really for the diarrhea? That's right. OK, let's try to get one more parasite in before our break. Yeah. So the next one is a parasite called Entamoeba histolytica. So this one is one of the nastier ones. It infects about 50 million people worldwide, and about 25 ,000 to 100 ,000 deaths are attributed to this parasite annually. Yeah, this is not cool.

41:24One of the reasons it's really hard to study this particular parasite is that there are other organisms in our gut that look almost exactly the same, and they are very closely related. And so for a long time, people had trouble identifying this as a cause of diarrhea because they'd be like, well, we see this when people have diarrhea. We also see this when people don't have diarrhea. And it took a while to figure out that they were looking at different organisms. So that means there are other amoeba in our guts that don't cause diarrhea. Yep. Wow. Yeah. I mean, I knew there were microbes living within us.

41:59I don't think I knew that they were like amoeba just like happily hanging out. Yeah. Wow, we do contain multitudes, don't we? We sure do. Yeah, we should bring Katrina on to see what she knows about that amoeba. But anyway, so I came across this interesting story that was mentioned in a couple different places. I haven't been able to trace it to the source yet, but I'm excited about it, so I'm going to share it anyway. Apparently, there's a guy named Fritz Schauden who was interested in trying to figure out the difference between the amoeba that cause disease and the amoeba that don't. And so it sounds like he purposefully infected himself with the ones that cause disease to prove it.

42:36Your favorite thing. My favorite thing. But one of the problems with this parasite is that so it goes into your intestine. It tends to live in like the mucus that lines your intestine. But every once in a while, it will start like essentially burrowing deeper and causing pathology like along your intestine. Or it will escape from your intestine entirely and go through your blood to different parts of the body. And this is how it ends up killing people. And so this poor guy, Fritz, he ended up getting a particularly bad case and died during a surgery to try to like deal with the complications from having it.

43:12But I think he showed pretty well that one of them is pathogenic and one of them is not. So anyway, this is definitely one of those where if you get it, you want to take medications to get rid of it. And we have amoeba sides to get rid of it. Amoeba sides. Wow. Amoeba sides. That's right. But why does one of them cause these complications and other amoebae don't? We don't know. We don't know? No, I don't think we know. Yeah, nope, I don't think we know. So Fritz Schaden gave his life in vain? No, no, I think it's important to know that there are some that cause disease and there are some that are just commensals.

43:46Because now, like, you can more easily diagnose somebody. And there's a lot of different causes of diarrhea, right? And so if you see this amoeba or if you see amoeba in the feces, you say to yourself, I've got to figure out if this is the bad amoeba or if they just happen to have some of the OK amoeba, because if they've got the bad amoeba, there's a bunch of additional complications I have to worry about in case this thing gets into their blood. And so now you like treat more aggressively. And a lot of people are thought to have irritable bowel syndrome when they actually have this parasite.

44:15Not like all of them. It's just this happens from time to time. And so, you know, I think it's important to know that this is a thing that can cause disease that kind of looks like irritable bowel. And you need to check into it in more detail. Yeah. All right. That's true. Okay. So we've done two parasites so far, Giardia and these amoebae. If you had to be infected by one of them, which would you choose? Giardia. Wow. There's no cause there at all. No way, man. I would not want Entamoeba histolytica. Like if this thing, the complications from this one are particularly nasty, this is one you want to avoid.

44:47Wow. But there's two more we get to talk about. And so let's take a break. And when we get back, we will talk about two more parasites that actually live inside of the cells in your intestine. Oh, boy.

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45:44Every sale comes down to a single second. The one between buy now and maybe later. PayPal is built to help your business win that moment. With a checkout experience that feels certain, reliable, and familiar. With a global two-sided network and hundreds of millions of buyers who already know us. all to keep you in control however buying happens next new markets new ai powered selling services a whole new agentic era where you decide how your business will show up and stand up paypal is built to help your business come out ahead we're built for payments built for growth Built for Agentec PayPal Open Built for all business Visit PayPalOpen.com to get started That's PayPalOpen.com Apple Vacations where your story starts The Summer Savings Event is here at Apple Vacations It's the perfect time to bring everyone together for the getaway you've been dreaming about Book between July 24th and August 27th and enjoy up to 55 % instant savings From relaxing beach days to unforgettable moments with the people who matter most, your next vacation starts here.

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47:50Okay, we're back and we are inducing nightmares. You know, I had a friend email me about our recent rat lungworm episode, and they were like, look, I came for the physics and I like the biology, but two parasitologists on the show at the same time is a little crazy. Oh, no. Was it too much for them? This sounds like it was actually a negative email. I've gotten a lot of nice feedback. My people like it. No, it was positive, but I think it was an intense experience for a lot of people, that episode, as it was for me. Yeah. And, you know, so to be honest, when we do one of these intense episodes, I sit back and I think, why are we doing this to people?

48:28And I think there's good reason. Like, you know, so I think you need to know how bad rat lungworm is so that you can, you know, one, pay attention to if it is coming to your area. And two, decide what kinds of risks you're willing to take with your food or know that you need to be managing your salads a little bit more carefully. I think these are things that are important to know about and tiptoeing around them might give you a false sense of security or like, I don't know, it was a chance to put something that I think is important on people's radar, even though it is real nasty. Totally agree.

49:03It's important that we know this stuff, especially if it's nasty and it's dangerous. but also totally valid response to say, wow, that was gross and hard to listen to. Yep. Yep. Yep. Yes. Well, and you know, if there's anything in particular, like a moment where it went too far, you all can let me know. And Daniel and Matt know that they can censor me when needed. And so I try to not go too deep into the gross stuff. No, this podcast is all about the joy of knowledge. And so people want to know, I mean, a lot of people wrote in and wanted to hear about this. So let's give it to them. All right.

49:36Here's some more knowledge for your brains. So cryptosporidiosis is caused by a couple different kinds of cryptosporidium parasites. Why is it called crypto? I mean, this has nothing to do with like investing in meme coins. This came before meme coins, bro. The meme coins are trying to be like cryptosporidium. Oh, okay. Why is it called crypto, though? Crypto usually means hidden or secret. Cryptozoology is like study of Bigfoot and Loch Ness Monster and stuff. So what's crypto about cryptosporidium? I am going to guess. On the record here, I don't actually know the answer, but there are parts of your stomach that are called crypts.

50:20Oh. And I am guessing that they are doing something in those little crypts, which are sort of like pretty deep inside of like the wall of your intestine. Oh, I see. Crypto like Crypt Keeper. Nice. All right. Yeah, yeah. I named a parasite the Crypt Keeper wasp. So anyway, which we talked about with Scott Egan. How common is this one? About 800 ,000 cases in the U.S. It's the second most common cause of diarrhea in kids. Oh, my gosh. So you were asking earlier, you know, of the, what, 10 ,000 pools of feces. And also, you're like, Kelly, you're gross. How many Olympic swimming pools full of poop are we talking about, Kelly?

50:57And so maybe you egg me on. Yeah, I think that's my rule here. Yeah. Yeah. All right. So a significant portion of those pools are probably filled by crypto, unfortunately. Wow. And crypto differs a bit from some of the other parasites we've been talking about, and that it tends to also be a problem for a lot of other animals like cattle. So there are farms where if the calves get this parasite, they're going, you know, maybe they'll die, but they also grow less well. So it's a problem for productivity. and Kay, who was one of the listeners who asked for like this episode, I think this is what she was referring to at the top of the episode where she was talking about how managing the massive quantities of manure that are produced on cattle farms is like an important public health problem.

51:42So you really need to make sure that cattle manure doesn't get washed into waterways because otherwise you might end up getting this parasite. Yeah. And so this parasite, just like the others, You know, it's a poop to mouth parasite. If you accidentally ingest the cysts that were excreted in feces, what this parasite does that's kind of interesting is it sticks to the surface of the cells that lie in your intestine. And then the micro those veli that we were talking about, they get longer and they fuse around it. And so now they make like a little intracellular space. And I don't know if like in some cases that's a good strategy for walling off parasites so they don't cause more problems and it just doesn't work in this case.

52:25Or if this is a situation where the parasite is manipulating the veli into making a little home for it. I don't think we know the answer. But now it's intracellular and it starts replicating inside of those cells. And when it's done, it bursts those cells open and goes off in search of new cells. And your immune system responds to all of that. And so this is a situation where probably some combination of like physical damage that is happening to your intestine because of the parasite and your immune system responding strongly to that might be what induces diarrhea. Interesting. And the same thing happens with cyclospora is also an intracellular parasite.

53:04I think the mechanisms are a little different, but the idea there is the same, that you're inside of the cells, you burst those cells open from time to time, and the immune system responds. You're definitely messing stuff up in your intestine. And you mentioned here that UV light is a powerful way to kill this parasite. Why don't we use UV light on all of our food? So I think the answer to that is if you were to buy like, what is it? A head or a heart of romaine lettuce? Why do we name them after body parts? It's a plant. I don't know. Should be called a knee of romaine lettuce. That's right. That's I think a foot, something.

53:40So if you get your foot of romaine lettuce and you go to pass it under a UV light, there's a lot of like crinkles and areas that probably won't get hit by that UV light. And if you've got something like, you know, romaine lettuce where multiple leaves are stuck together, then there's going to be areas that don't get hit by that UV light. And you'd have to worry about, I guess, either rotating it or getting it on both sides as it goes through. This just seems to me like a method that could convince you that you've done a good job of cleaning your food, but it would be very easy to miss areas with the UV light just because it's not like a sheet where it's easy to get it all.

54:19Interesting. I know that UV light passes through water fairly easily. Like you can get a sunburn even if you're underwater. But I think the outer layers of lettuce cells will not let you be through. So you're right that like the inner layers won't. But more broadly, why don't we use radiation? I think a listener recently wrote in and asked about why we don't use radiation more often to make our food safe. Yeah, I don't know the answer. My guess would be, again, that it's hard to make sure you got everything. Do you think the radiation could damage the plant cells in some way that would make the food less tasty?

54:55I don't know. Perhaps. My guess without doing a lot of research is that radiation sounds yucky to people. And they don't want to eat food that's been irradiated because maybe it's going to make them have a third eyeball or poop green slime or something like that. Yeah. Since Three Mile Island, radiation has a pretty bad rap. Yeah, unfortunately. but another thing that's tough about this parasite is that chlorine doesn't do a great job of killing it and so this is one of the reasons where if a kid poops in the pool everybody's got to go out because just a little bit of chlorine bumping up the chlorine just a little bit isn't going to do the trick so like as i understand it if a kid is wearing a diaper and they do a solid turd in their diaper everybody has to get out and they bump up the chlorine a little bit and they call it a day But if someone has diarrhea and you're worried about crypto, everybody has to get out and they bump the chlorine up massively.

55:51And people have to stay out because the chlorine levels are like, you know, burn your skin level high. And you have to wait until the levels go back down again. And so that's why diarrhea can shut down a pool. How do the levels go back down? You just got to add fresh water? I think the chlorine evaporates off over time. Oh, no, actually, I think the radiation breaks down the chlorine. Oh, OK. The sun's radiation. Yeah. Yeah. Interesting. All I know is I need to keep adding chlorine to my pool. It's not building up over time. But yeah, so crypto in particular is a parasite that we worry about in pools.

56:22And it's not cool that it's so hard to kill it with chlorine. And so finally, we get to cyclosporiasis, which is what we are all concerned about today. The newly famous parasite. The newly famous parasite. One of the things that's interesting about this parasite is that it was a thing that we weren't super worried about from a public health perspective in the United States for a while. But in recent years, we've been seeing more and more outbreaks caused by this parasite. We don't exactly know why. Maybe something about changes in temperatures are making it so that the cysts can survive in the environment for longer.

57:00Daniel eating so many bagged salads. Daniel in particular is the source of cyclo for everybody. he's got to stop pooping in the lakes and in the pools and on the raspberries. Wow. You just took a little joke and went way too far with it. I feel like that's usually your job, but sometimes. All right. Well, I'm going to take heart in the fact that you're not mad at the beavers for pooping in the water. And so - You know better, man. You know better. I know where you're going with this. You know better. All right. So anyway, we're seeing more outbreaks. Part of this could be because we're better at detecting it in the environment.

57:40So like for a long time, we didn't even have the genome of this parasite so that we could do proper tracing. But we've got the genome now. We have more tools. And if we would just stop firing the people who use these tools, we might be in a better position. But anyway, so this is something that's more often a problem in Canada, Poland, the United Kingdom, the United States than we've seen in the past. And it's the basic story the same. You're eating the cyst and then it latches on somewhere inside you and it grows and makes more cysts. And for reasons we don't understand, it induces diarrhea and the cysts come out in your diarrhea.

58:13Yes. So one thing that's sort of interesting and a little bit different about this parasite is, you know, for all of the parasite, it takes about a week for, I'm guessing, the damage to your intestines to build up and then you start having diarrhea. But a lot of the parasites, once the parasite gets into the environment again, it's ready to infect the next host. This parasite needs something like a week depending on temperature. We haven't really been able to study this in the wild very well, but it needs a little while to mature in the environment. And so this means that you don't often get cyclospora passing from, you know, for example, somebody at a daycare center changing a kid's diaper and like passing to the other kids if hands don't get washed because you've got like a week to disinfect all of your surfaces.

59:01So it doesn't usually go from person to person. But if it's in the produce and then it gets shipped around the country, it takes about a week for that to happen. Now the parasite is ready to infect people. And then it takes another week for symptoms to show up. And lots of parasite stories we've heard on this podcast involve like hilarious, different situations. Like it comes out of this creature and then it's got to go up the nose of that one. And then it has to be on the hairs of this guy. Whereas Cyclo seems to only grow in the guts of humans. Why isn't there some Rube Goldberg complicated life story here?

59:35I mean, I feel like it's still pretty complicated. It needs to be out in the environment for like a week and then it can get into people. But some of the other parasites that we've been talking about, some of it is complicated. Well, like, so what makes Giordia, for example, more complicated. It seems to me that it's less complicated that it can live in a beaver. It can live in a human. It's come up with like a more generalist way of doing things. Whereas cyclo is like pretty specific. You know, it needs to get into a human. We think there have been some studies suggesting maybe it can live in a couple other animals.

1:00:08This is like an active area of research. But cyclospora is one of the more human specific pathogens that we've talked about, like Like Cryptosporidium, there's a lot of different species that infect a lot of different animals, and some of them can also infect humans. But Cyclo is pretty specific. All right. So I think what a lot of people want to know is, Kelly, you're a parasitologist. We're reading a lot of stuff in the news. Nobody really knows what's going on. What should we do? Should we eat bagged salad? Should we only eat canned food and heat it up to 170 degrees? Tell us how to stay safe, Kelly.

1:00:40All right. So first of all, if you are a person who's immunocompromised, you need to be extra careful, unfortunately. People can make a decision for themselves about whether or not they're feeling comfortable eating bagged salads at this point where we don't feel like we've wrapped up all of the details about the current outbreak. I am personally rinsing and hoping it's okay because I feel like the benefits of salad for me outweigh the risks when it looks like we've already identified Taylor Farms as the source. So I'm okay with eating some other salads. But if I was immunocompromised or my kid was, I might make a totally different decision.

1:01:15Right. And so what I can suggest is that websites like the CDC and the Food and Drug Administration and the World Health Organization, all of those websites have advice for how to keep yourself safe. And you should definitely listen to those instead of listening to Kelly. But here are some things that they are going to tell you. they're going to tell you that you should wash your hands regularly especially before you go to eat and especially if you've been touching livestock if you've been at a petting zoo or if you've been changing diapers you should really carefully wash your hands and sanitize any surfaces that you've touched do not swallow water at public pools i'm looking at you son of mine.

1:01:59You need to stop doing that. Don't drink water from pools, rivers, lakes, et cetera, unless you have treated it. So there are certain kinds of filters you can buy and there are tips for how long you need to boil water to make sure that you've killed these things. If you are going hiking or you think the apocalypse is coming, you should read up on what to do if you are going to be drinking water that hasn't been properly sanitized beforehand. You should support programs that make sure livestock waste can't get into your waterways, you should be a little concerned that we're firing some of the people who track this stuff down.

1:02:36Those people have important jobs and they need help. Be a little bit cognizant when you're being intimate with your partner about whether you might have come in contact with feces. If you've had diarrhea recently, give it a break for a week. And, you know, try to make sure you're not passing anything to your partners. If you go to an area where these parasites are much more common, keep in mind that people who live in these areas are more likely to be asymptomatic than the rest of us. It could be because throughout their lives they've been exposed to this parasite at a low level and their immune systems are better able to handle it.

1:03:11But a lot of times if someone from a developed country goes to a less developed country where the parasite is common, even if everyone else is drinking the tap water and putting the ice in their drinks and they're fine, you might not be. And so if you go to one of these areas, you should drink bottled water. You shouldn't put ice in that water. And you should maybe only eat foods that have been cooked well. So keep in mind that raw fruits and vegetables that have been rinsed in tap water might have the parasite on it. So if you're going to eat fruits, you know, if you want a banana or something, maybe you should go ahead and peel that banana because the inside probably isn't infected with something.

1:03:48But there could be some parasites on the outside. Yeah. And before you travel, you should always check websites like the CDC and the World Health Organization to see what their advice is for when you go to one of those places. So there are ways to keep yourself safe. And one of those ways is by supporting the people whose job it is to try to make sure that you stay safe. That sounds like solid advice. All right. So give us Kelly's prediction for the future. Do you think we are facing every year bigger and bigger outbreaks of these parasites? Or do you think we're going to figure it out and get it under control?

1:04:23Or what does the world look like for our kids, Kelly? If you were to draw a trend line for cyclospora in the United States, I think you would see cases increasing over time. I don't think that we are powerless in the face of that trend. I think that we could amp up our surveillance and be more careful both at like the company level and at the level of reporting when people start getting diarrhea, figuring out what it is and reporting that kind of stuff. So, you know, I never like to be negative. I like to be gross, but not negative. So there are things we can do. And so I'm going to hope that we do those things.

1:05:00All right. Well, I think it's always better to know. So thank you for taking us on this sometimes uncomfortable, but very educational journey. Yep. I hope none of you have gotten cyclospora. And wash your hands. Stay clean and stay safe, everybody.

1:05:22Thanks, everybody, for listening. Please go and do us a favor and rate the show on whatever podcast app you're using. It really helps people find us. Daniel and Kelly's Extraordinary Universe is edited by the amazing Matt Kesselman. He really is a wizard. You can also find us online on Blue Sky, Instagram, and XDNKUniverse. Come engage with us. You can email us at questions at danielandkelly.org. We really do want to hear from you. And you can find our website, www.danielandkelly.org, where you'll also find an invitation to join our Discord, where everybody comes and talks about the amazing universe.

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