‘Explosive’ diarrhea illness reported across US. See map of affected states

You may want to be more mindful of your plate of fresh fruits and vegetables this holiday weekend: A parasite that causes explosive diarrhea is behind rising cases of food poisoning during the summer months just before Independence Day.

Cyclosporiasis, a stomach-churning illness caused by a parasite often found in produce, has sickened hundreds of people in more than 17 U.S. states since May 1, according to the Centers for Disease Control and Prevention (CDC) and state health data. One state, Michigan, a group is fighting an infection It more than tripled the total number of cases compared to 2025.

While state health authorities, the CDC, and the Food and Drug Administration (FDA) are working to identify a common thread between the illnesses, no singularly related outbreak has been identified. Instead, cases so far appear to be part of a seasonal surge, although authorities are looking for a potential pathway.

“CDC has no evidence of a single, multi-state Cyclospora outbreak currently occurring that connects the cases reported in the press,” the agency told USA TODAY in a June 2 statement. “The data currently available on the CDC’s website is the number of surveillance cases of people with cyclosporiasis across the United States. This number includes clusters of cases currently under investigation by the FDA and cases that are not linked to a common source.”

Here’s what you need to know about avoiding parasite infection when picnicking on the Fourth of July and beyond, including where it’s been detected so far.

What is cyclosporiasis? What are the symptoms?

Cyclosporiasis is a parasitic infection that causes uncomfortable gastrointestinal symptoms often associated with food poisoning, such as diarrhea, nausea, and vomiting. It is caused by the parasite Cyclospora cayetanensis, also known simply as cyclospora, and is usually transmitted through contaminated food.

The most common symptom is watery, frequent and sometimes “explosive” diarrhea, according to the CDC. Cleveland Clinicbut other stomach problems may include:

• Bloating or stomach cramps, including burping and gas

• Extreme tiredness (fatigue)

See states with cases of cyclosporiasis

The CDC tracks cyclosporiasis cases based on where they were contracted. As of June 16, 145 people in 17 states in the United States were infected after eating the food. Another 45 people, who were tracked and categorized separately, contracted the disease while traveling abroad.

Of the 145 people who got sick in the US, 20 were hospitalized and none died. Cases were seen in people aged between 5 and 86, with an average age of 42. According to the CDC, the cyclosporiasis “season,” or months that typically see a spike in the disease in the U.S., begins May 1 and lasts through the end of August.

However, these numbers do not include more. 150 people got sick in Michigan after the first case was discovered in the state on June 22. On July 1, the state’s health department said “more than 170 cases” had been reported; That’s a significant increase from last year’s statewide total of about 50.

The CDC told USA TODAY in a July 2 statement that it did not have new data to provide and that its surveillance dashboard for cyclosporiasis infections is updated monthly. The map below reflects latest CDC data available As of June 16 and additional state level Reporting as of June 30.

How to avoid contracting a parasite that causes diarrhea?

Cyclosporiasis is transmitted via the fecal-oral route, meaning contact with food, drinks, and surfaces contaminated with infected poop particles. Often this means consuming the affected food or drink directly, or touching something contaminated and then touching your mouth without washing your hands.

According to the CDC, we often see an increase in cyclosporiasis infections during the hot summer months due to infected fecal matter contaminating fresh, summer produce like basil, raspberries, and lettuce, all of which have been linked to past U.S. outbreaks.

While outbreaks are more common in tropical or subtropical regions of the world, such as Central America, South America, and Africa, contaminated and unwashed produce tends to cause spikes during hot weather in the United States, Michigan Department of Health and Human Services. I previously told the Detroit Free PressPart of the USA TODAY network.

People usually become sick about a week after exposure, but symptoms can appear in as little as two days and as much as two weeks later.

The infection is treated with antibiotics, and while most healthy people can probably fight it off on their own, long-term, untreated illness can last for months and recur, according to the CDC. As is often the case, children, the elderly, and those with compromised immune systems are more likely to become seriously ill or even die, and should contact a healthcare professional if they become ill.

To prevent contracting cyclosporiasis, first HKM, Cleveland Clinic And Michigan Department of Health I recommend you to:

• Avoid consuming food or water that may be contaminated with feces. Avoid drinking or cooking with unpurified water.

• Wash your hands with soap and water after using the bathroom and before, during and after preparing food.

• Wash all food preparation surfaces, including utensils, cutting boards, and counters, before and after use.

• Wash and peel vegetables before eating; Thoroughly scrub skinned produce such as melons and cucumbers; Cut off any damaged or bruised areas on fruits and vegetables before preparing and eating them.

• Store prepared fruits and vegetables in the refrigerator as soon as possible (within two hours).

Credit: Kristen Jordan Shamus, Detroit Free Press; Sara Moniuszko, USA TODAY

This article first appeared on USA TODAY: ‘Explosive’ diarrheal illness reported across the US. See map of affected states