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[email protected]. Infectious diseases, research, medicine, health, welcome to Outbreak News interviews. And now broadcasting from the Outbreak News Skylar Studios in beautiful West Central Florida, here is your host, microbiologist and editor of OutbreakNewsToday.com, Robert Hariman. Hey everybody and welcome to today's podcast. My name is Robert Hariman and this is OutbreakNews Interviews. And just in the past week, I reported on cyclospor outbreaks in Ontario, Canada, down here in Texas, and even in increasing cases in New York City on the website, OutbreakNewsToday.com. Well joining me now for our latest installment of the weekly feature, Parasites 101, is Parasetologist and author of the book Parasites, Tales of Humanities Most Unwelcome Guest, Rosemary Drisdell. Hi Rosemary and welcome back to the podcast. Robert. Well like I said in the intro, cyclospor has been in the news in recent weeks. Last week we discussed Aschrist Lumbercoides which is an nematode or a roundworm. Cyclospor is a protozoa. So let's start out with what is a protozoa and then what is cyclospor? We've gone from quite a large parasite to a very tiny one. protozoa are single-celled organisms. They are complex cells so they have organelles inside. They're not the simplest single cells that you can find, but they are nevertheless very tiny microscopic. They include the amoebas, the phlegalus, the siliates, and a group of coxidia of which cyclospor is one. So cyclospor is a spherical organism. The infective state we call an uocyst. It's about 10 to 12 microns. So sorry, 8 to 10 microns or about 10 1,000th of a millimeter in size. So you can imagine how impossible it would be for anybody to know that such a thing was present. If you swallow enough of them, then they make you ill. Okay, so geographically where is cyclospor found? Well if you look at a map for cyclospor you'll see that it can show up just about anywhere. But it does tend to lurk in the tropics. It escapes from the tropics generally in outbreak situations. So it seems like it probably originates in the tropics, but it is a human parasite. So it can survive anywhere where there are humans to infect basically. And it does tend to appear in the spring and summer. This is the time of year when we typically nowadays see outbreaks of cyclospora, particularly in North of America. Right. And how prevalent is like with sporeasis in North America in the US and in Canada? Yeah, it's not particularly prevalent. As I said, it generally occurs as outbreaks. The CDC has some data which says from 2000 to 2015 there were 32 such outbreaks, a total of about 1600 individual cases and the largest of those outbreaks involved almost 600 people. But this is likely only the tip of the iceberg. Many cases will go undiagnosed. Now who is at risk for infection with cyclospora? Absolutely anybody. Anybody who swallows these uisists in sufficient numbers and the number is probably really quite small. It tends to be small with the coccytia. You wouldn't have to eat very many of them to become ill and absolutely anybody, any age anywhere. Okay, so that pretty much answers my next question. How did somebody contract it? It's via contaminated water, contaminated food. Yes. And it's often fresh produce, things like salad mixes, things like herbs like basil or vegetables like snow peas, cilantro, often things that have been imported from Central or South America to the United States and Canada. Now unlike other coccytian parasites, many listeners may be familiar with one called cryptosporidium. Correct. Direct fecal oral transmission canadacruid with cyclospora and that's kind of unique for cyclospora. Can you explain why that is? And can you also discuss the life cycle of cyclospora? Sure, it's interesting with cryptosporidium and you're right that is much more familiar to people and tends to cause much bigger outbreaks. A person can pass that directly. So if they have the uisists on their hands and somebody else swallows some of those uisists, they can get ill. It happens that quickly but with cyclospora it doesn't work that way. And this is because when the uisists are passed in the stool, they're not what we call "spoilated, they're not mature or infective" and so they need a period of time in the environment in order to go through that stage and become infective. This probably gives us a clue as to why it tends to come from the tropics because of the climate there. The climate is warm enough that at virtually any time of year cyclospora can probably complete its life cycle, whereas up here in Canada and even in the United States in a lot of places, the weather is just too cold for much of the year for cyclospora to complete that life cycle. So when we swallow the uisist, it contains tiny organisms even smaller than the uisists. These are called sporozoids and they exist. They come out of that uisist in the intestine and then they invade intestinal cells. They go through a period of multiplication and this is asexual multiplication. So it's just a binary fission kind of thing where they multiply, they burst out of the cell, they re-invade new cells and they can go through several generations of this type of asexual multiplication before eventually male and female parasites are formed. And then when they go through sexual multiplication, we get the production of the uisist and the uisists are then passing the feces and again they need a little bit of time in the environment in order to become infective. Now are the symptoms of cyclosporiasis like other protozoan infections? They are fairly typical. They're not very similar to cryptosporiosis. Actually, you get a severe type of diarrhea. You might suffer some loss of appetite along with some nausea, maybe vomiting. Of course, you tend to lose weight if you're not eating and you're throwing up. Abdominal discomfort like cramping and bloating gas, that kind of thing. And also typical of this kind of illness and fatigue, maybe even some fever. The thing about cyclosporiasis that is very disconcerting is that it tends to last for a long time. So it can last for several weeks, even more than a month. And the symptoms tend to kind of come and go, so you might think you're getting better and then your symptoms come back. So it really can be quite prolonged and quite uncomfortable. Is this known as a lethal disease? No, it is usually self-limiting, even if you're not treated, you'll eventually get over it yourself. Very in very rare cases. Of course, in small children, you have to worry about dehydration, but in most cases, cyclosporiasis would not be fatal. Okay, great. Let me go ahead and go to my sponsor real quick. Now, for many years, we have been waiting for a Lyme disease test that actually works. 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[email protected]. All right, Rosemary, how does the laboratory diagnose cyclospora? The physician would ask the patient to send a stool sample to the lab. And in the lab, we have concentration methods, which help us to separate out all the garbage and digested food and that sort of thing from a stool sample and concentrate any parasites that are present. So this makes it much easier for us to see cyclospora in a stool sample. We would read it on a wet mount. There are some special stains. It's a bit more challenging to identify cyclospora in a stool than it is for some of the other protozoa because it doesn't stay in well with the routine stains that we use. So we have to do some special methods sometimes. But once you know what cyclospora looks like, it's one of the
those things when you see it on your slide and you say, oh, look at that. That's a cyclospor. They look a bit like beach balls with one side kicked in, if you know what I mean. Yes, I'm very familiar. Now, you mentioned earlier, it's a self-limiting infection mostly, but sometimes treatment is necessary. And the treatment for cyclospor is a common antibiotic. That's right. It's traumatic for himself up. And that's also unusual amongst the Cocks City because they have been traditionally very difficult to treat. So it's delightful that this particular one is quite sensitive to a common antibiotic. But one of the possible problems is, I mean, some people are allergic to septera and bactrum, the trade names for tri-methodromosulfa. What do they do if someone's allergic? The second choice would be sipproflocicin. And if you absolutely can't treat with antibiotics, then you would simply provide supportive treatment. Make sure the patient doesn't get dehydrated and treat them for their symptoms. And eventually, like I said, they will clear the parasite on their own. Very good. Now, I don't remember hearing much about this parasite when I was a student back in the 80s. However, that really all changed in the 1990s. What happened? Well, we didn't know about it until the early 1990s. We did know about cryptosporidium a few years before that. And it was the advent of cryptosporidium, really, that alerted us to the fact that there was something else there that turned out to be cyclospora. So at first, people would see things that looked like cryptosporidium in stool samples, but were too big and weren't quite typical. And they would wonder what these were. But eventually, we realized that we were dealing with another coxidian. Yeah. And I think it was in the 90s when we heard about that big outbreak that kind of came out of nowhere in raspberries from Guatemala or Honduras. Yes. That's right. Do you recall that? I do recall. At first, there was some talk of it being strawberries, but eventually, they did narrow it down to raspberries from Guatemala, which subsequently resulted in a lot of import restrictions and rules and instructions on berry farms and things like that. Yes. And after that, we realized that it wasn't just raspberries. It was all kinds of other things that were being imported from Central and South America and even some of the Caribbean islands. Right. Now, how about prevention of cyclospora? The best way to prevent cyclospora is to make sure that food isn't contaminated with it, which of course is quite quite a challenge, especially when this food is coming from other countries, where you don't necessarily have as much control over the conditions on farms and things. But making sure that you're not using contaminated water to irrigate your fields, making sure that your farm workers have proper sanitation, that they have good hygiene, and all along the chain where these foods are picked, shipped, packaged, handled by anybody, you have to make sure that their protective farm being contaminated. The chemicals that we often use to sterilize water and to kill things in water don't work very well for cyclospora. Chlorine is the one that obviously comes to mind, not very effective. And of course, the difficulty is, and it's often difficult to identify the source. We're often not sure exactly where it started. In outbreaks, people, of course, usually have eaten some people eaten or rest aren't over here and some ate somewhere else and various gatherings. And so it can be very difficult to pinpoint where people are getting it and then what the food is and then where it came from. So it's a difficult chain to follow. Yeah, that is true. I have noticed that all the outbreaks that are going on right now, that up in your country and down here, you know, you always hear investigation is ongoing. And this goes on for weeks and weeks and weeks. And I'm member in 2013. I actually interviewed Dr. Patricia Quinless. She's the top doctor for public health in the state of Iowa when they got hundreds and hundreds of cases in Iowa. And they had, they struggled for the longest time trying to pinpoint the source of that cyclospora. And sometimes there is no answer. There is never is a solution. And the other thing too is Robert that in many paracetology labs now, they are, there's a flow chart. And so if you have a patient who hasn't been traveling and they have a typical diarrhea, they're not going to get tested for all of the various protozoa that it could be. They're probably only going to get screened for maybe GRD and cryptosporidium. And so if there's a cyclospora outbreak going on, it may take time for people to realize that because they're not going to catch it. Good point. All right, Rosemary, this is the part I always look forward to. You got any interesting or unusual nuggets this week about cyclospora? There was a really interesting outbreak that happened in 2000 and it fits right in with our conversation about the raspberries. 83 people attending a wedding out of those 83, 54 subsequently came down with cyclosporiasis. And the food item that was eventually implicated was none other than the wedding cake itself, which had a raspberry cream filling. They were able to isolate cyclospora DNA from that raspberry cream filling. So here you could say that everything just came together perfectly. We had an easily identifiable group of people. We knew exactly where and when they ate the offending food item. There were a limited number of potential foods. And the one that was responsible was one of the traditional ones that we keep. People tend to keep a piece of their wedding cake, right? So it was still available several weeks after the event so that it could be tested. So here we had all these things coming together to give us a very clear answer. And back in 2000, there were still a lot of questions. And this particular outbreak answered a number of them definitively. And a bad memory for the happy couple, but a great result for identifying risk factors and sources. And being sure. Well, I knew I could count on you to bring up something that I totally missed on my radar. That's a good one. All right. Well, thank you very much. Once again, Rosemary Drisdell for another enlightening interview. I appreciate it. Oh, thank you. Always a pleasure. Okay. Bye-bye.
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