The foodborne illness cyclosporiasis has become a national concern, with the Centers for Disease Control & Prevention reporting more than 7,000 cases nationwide.
In Missouri, hundreds of people have fallen ill after products identified as potential sources in the outbreak reached grocery store shelves across the state.
KBIA's Najifa Farhat spoke with Nathan Koffarnus, an epidemiologist at the Missouri Department of Health and Senior Services, for a deeper look at how the parasite spreads, what health officials know so far, and how Missourians can protect themselves without falling for misinformation.
This interview has been edited for length and clarity.
Najifa Farhat: So, how different is this cyclospora outbreak compared to the other foodborne illnesses?
Nathan Koffarnus: There are some difficulties specific to cyclospora. One of those is just the amount of time that the disease can incubate before people develop symptoms. And so, what an incubation period is: it’s the time between when you get exposed to a cause of illness and when you actually develop symptoms. And with cyclospora for most people, that's about a week, but it can be anywhere from two days to two weeks.
Najifa Farhat: This parasite has existed for a long time. Why has this become so big this year?
Nathan Koffarnus: So with cyclosporiasis, the contamination mostly happens in the growing season. I guess there could be anytime its food would be exposed to water. If the water was contaminated, it could be a problem. But usually that's an irrigation process.
"And with cyclospora for most people, that's about a week, but it can be anywhere from two days to two weeks"
- DHSS Epidemiologist Nathan Koffarnus
This disease is usually an endemic disease in a lot of countries. And what endemic means is: when the disease is present there all the time. So, it just continually gets transmitted from person to person. Here in the United States, I wouldn't consider it endemic. We have a very defined season every year from May to August where we see the vast majority of our cases. It doesn't just transmit year round. And basically, most of those cases are tied to either people traveling out of the country during that time period and now bringing it back. Or it can also be – from time to time, like we have this year with imported produce that's coming into the country that's been contaminated.
Najifa Farhat: Have you identified any single source of contamination in Missouri?
Nathan Koffarnus: So that's something we're working on. I would say we don't have anything at this point in time definitively or unique that's different from what's being seen elsewhere. But there's a possibility we could find more as we go. One of the difficulties is that the cases have been coming in so rapidly. We're certainly looking for clusters.
Najifa Farhat: Now let's talk a little bit about all the contradictory information the public has been getting about the source of this parasite. I feel like there's a lot of miscommunication from the agency's side to a general population who don't probably understand all the differences between environmental findings versus epidemiological findings. So could you clarify this whole fiasco for us?
Nathan Koffarnus: So my understanding with the false positive, at least what's been publicized nationally and put out in national statements, is that they kind of did a rapid test, thought they had a positive and reported that out. And then ultimately when they did confirmatory testing, they couldn't duplicate the results. And that happens sometimes.
But that same producer is still being— the recall is still in place for that producer. They're still being looked at as one of the primary sources, if not the primary source of this outbreak.
"You definitely want to rinse your fruits and vegetables. That helps. If they're tough enough to stand it, scrubbing them is a really good idea too, just to get extra spores off."
- DHSS Epidemiologist Nathan Koffarnus
And that's really based on the interview data that we get from interviewing thousands and thousands of cases across the US. So that's why you see CDC and FDA come out and say, “No, we're still really certain that this is cause and what we're looking into,” and that's why they're not backing down because you know they do have a lot of good data that supports that there was a problem coming from that particular producer.
Najifa Farhat: So what would your advice be, you know, regarding choices of food or what kind of food people should be eating just at this moment, because there's a situation going on?
Nathan Koffarnus: So really, it's those ready to eat fruits and vegetables that you don't cook that you just kind of like some people wouldn't even rinse them. You definitely want to rinse your fruits and vegetables. That helps. If they're tough enough to stand it, scrubbing them is a really good idea too, just to get extra spores off. You can look at where they come from. So that could be a factor. Again, there has been some pretty public information made about areas that have been implemented so far in this. So that's a factor.
Again, if it's an imported product versus domestic, that's something you could consider. And then if you're just really worried, you can make it kind of a temporary switch to like cooked fruits and vegetables and things like that, because heating them does really kill this parasite pretty effectively.
