Wisconsin health officials are continuing to investigate cases of cyclosporiasis in the state. It’s a gastrointestinal illness caused by a microscopic parasite, cyclospora.
Thousands of cases have been reported nationwide. In Wisconsin, the Department of Health Services reported 105 cases as of July 22, including three hospitalizations. Most have been linked to international travel. Health officials are still working to determine the cause of the cases not linked to travel.
To learn more about the parasite and the illness it causes, WUWM Eric Von Fellow Akira Quinn spoke with Greg DeMuri, a pediatric infectious disease doctor and professor in the Division of Infectious Diseases at UW Health.
This conversation has been edited for length and clarity.
Akira Quinn: What exactly is cyclospora, and how do people get it?
Dr. Greg DeMuri: Cyclospora is a parasite. It's a very small parasite compared to some other parasites. It's clearly not visible with the naked eye. And it's transmitted through contact with human feces that have been around in soils. And that's really the only way to get it. It's not carried by animals, so you have to have some type of contact with human feces.
Is this the first outbreak of cyclospora?
It's not the first outbreak. I think this is one of the worst. We didn't know too much about this bug until about 10 or 15 years ago. And then we understood it a lot more, that patients with a weakened immune system can get it. So, when the HIV epidemic came about, we learned a little bit about it.
But one of the first outbreaks was associated with raspberries. And so, you'll see this association between cyclospora and raspberries frequently, and that's because of that one outbreak. But it really can be from different fruits and vegetables. So far, that's all we've ever seen is fruits and vegetables in our food supply.
Who is at most risk of complications?
It's those with weakened immune systems — so, you know, people who take medications that weaken their immune system, people who naturally have a weakened immune systems, young children and older people.
What symptoms should parents watch for?
Explosive diarrhea is what we keep hearing. And that's really true. So, diffuse diarrhea that's persistent, those blowouts in the diaper, diarrhea that is watery, bloating, excess gas, even nausea. And vomiting, on the other end of the GI tract, can be part of it as well.
What practical steps can parents take to reduce the risk of cyclospora?
First and foremost, if we know there's a certain product that's been recalled, check your fridges for that product and throw it away, or return it.
And then rinsing vegetables helps. It doesn't kill the parasite, but it can help wash off excess parasites that are there. Cooking does help, and it will kill the parasites. And that's about the only thing that'll kill it.
Of course, we want people to eat fruits and vegetables, which are healthy. So right now, avoiding shredded lettuce is wise until this can all get sorted out a little bit more, but there are plenty of other good fruits and vegetables to feed your children.
Have public health officials determined the source of the cyclospora outbreak?
It's tentative right now with the shredded lettuce. Most of the time it's actually hard to pinpoint the source by testing and detecting the parasite, because it's present in such low concentrations or low numbers. So, most of the information we get is from epidemiology and statistical analysis that's done — just asking people, "Hey, what'd you eat in the past two weeks?" And, you know, if everybody who's had cyclospora eats a certain fruit or vegetable, or in this case, shredded lettuce, then that implicates that product. But otherwise, it's really hard to test it on the food itself.
More information can be found on the Wisconsin Department of Health Services website.
