A parasite known for causing “explosive diarrhea” is spreading across the country this summer, and health officials say the numbers keep climbing.
Cyclospora, a foodborne parasite that targets the gut, has now been reported in 17 states. The Centers for Disease Control and Prevention says it had logged 145 U.S. cases as of June 16, and the totals have only grown since then. Michigan alone saw its case count jump from 170 on June 30 to 572 by July, according to that state’s health department.
So what exactly is this parasite, and why is it causing so much trouble?
“Cyclospora is a foodborne parasite that gets into people’s bodies, particularly their gut, and causes a diarrheal illness,” said Dr. Steven Goldberg, chief medical officer for HealthTrackRx, an outpatient infectious disease laboratory.
Which foods carry the risk
Cyclospora tends to show up on fresh produce with rough or uneven surfaces, the kind of texture that gives the parasite plenty of places to hide. Foods linked to past outbreaks include:
- Parsley
- Cilantro
- Snow peas
- Mesclun lettuce
- Spinach
- Salad mixes
- Raspberries, blueberries and blackberries
Goldberg explained that the bumpy, irregular surfaces on these items make them harder to clean thoroughly, which gives the parasite a better chance of surviving a quick rinse.
Unlike many illnesses, cyclospora doesn’t spread from person to person. It travels through contaminated food.
“The way this spreads is from a person having diarrhea and some of that material getting into either food prep or food service,” Goldberg said.
Cases tend to follow a pattern tied to the calendar. Cyclosporiasis season typically runs from May 1 through Aug. 31, with infections rising in the warmer spring and summer months. Since 2013, FDA investigations have tied 21 outbreak cases to cyclospora, most often connected to fresh herbs and leafy greens found in salad mixes.
Symptoms to watch for
Goldberg says what sets cyclospora apart from other diarrhea-causing organisms is the intensity of the symptoms. The CDC lists the most common signs as:
- Watery diarrhea (the top symptom)
- Loss of appetite
- Weight loss
- Cramping
- Bloating
- Increased gas
- Nausea
- Fatigue
Less commonly, people may also experience vomiting, body aches, headaches, a low-grade fever, or other flu-like symptoms.
Most people recover within a matter of days, but some cases linger or turn severe enough to require antibiotics. Goldberg recommends seeking medical care if symptoms include a fever, ongoing nausea or vomiting, persistent diarrhea, or trouble keeping fluids down.
How to protect yourself
The CDC recommends going beyond a quick rinse under the faucet. Goldberg agrees, saying produce needs real scrubbing, not just soaking.
“If you’re going to a farmer’s market or other area and you purchase food, that food has to have a prep process other than just soaking in water. It needs to be washed with a forceful water flow and manually cleaned,” he said.
The CDC’s broader prevention tips include:
- Wash hands with soap and water before and after handling raw fruits and vegetables
- Rinse all produce thoroughly under running water before eating, cutting or cooking it
- Skip rewashing produce already labeled “prewashed”
- Scrub firm items like melons and cucumbers with a clean produce brush
- Cut away any bruised or damaged spots before eating
- Refrigerate cut, peeled or cooked produce within two hours
Health officials haven’t tied all the current cases to a single multistate outbreak, but the overall trend is concerning them. The CDC says cyclospora has increasingly turned up on produce grown right here in the U.S. in recent years.
“We’re seeing now this year an acceleration of food-related illness in the United States. We don’t have a single explanation for it. It’s not clear if it is coming from farms or if there are other sources involved,” Goldberg said.