150 people infected in 7 Michigan counties
Since June 22, more than 150 people in seven Michigan counties have contracted cysticercosis. 14 people were hospitalized.
You may want to be extra careful with your fresh fruit and vegetable platter this weekend. A parasite that causes explosive diarrhea lurks behind the summer spike in food poisoning cases just before Independence Day.
Cyclosporiasis, a disease that causes abdominal pain caused by a parasite commonly found in produce, has sickened hundreds of people in more than 17 U.S. states since May 1, according to Centers for Disease Control and Prevention (CDC) and state health data. One state, Michigan, is already battling an outbreak that has more than tripled the total number of cases compared to 2025.
State health officials, the CDC, and the Food and Drug Administration (FDA) are working to identify commonalities between these illnesses, but no specifically related outbreaks have yet been identified. Instead, the number of cases so far appears to be part of a seasonal surge, although authorities are looking for potential outbreaks.
“CDC has no evidence linking a single Cyclospora outbreak in multiple states to the cases currently occurring and reported in the press,” the agency said in a June 2 statement to USA TODAY. “The data currently found on the CDC website is the number of surveillance cases of cysticercosis across the United States. This number includes cases currently under investigation by the FDA and cases not linked to a common source.”
Here’s what you need to know to avoid parasitic infections while picnicking this Fourth of July and beyond, including where parasitic infections have been detected so far.
What is cyclosporosis? What are the symptoms?
Cyclosporiasis is a parasitic infection that causes unpleasant gastrointestinal symptoms associated with food poisoning, such as diarrhea, nausea, and vomiting. It is caused by the parasite Cyclospora caietanensis, also known simply as Cyclospora, and is usually transmitted through contaminated food.
According to the CDC and Cleveland Clinic, the most common symptom is watery, frequent, and sometimes “explosive” diarrhea, but other stomach problems include:
- loss of appetite
- Bloating, including belching and gas, or stomach cramps
- Extreme fatigue (malaise)
- heat
- nausea
- vomiting
See states with cyclosporosis cases
The CDC tracks cysticercosis cases based on where they were infected. As of June 16, 145 people in 17 states have become infected after consuming food in the United States. A further 45 people were infected while traveling abroad and are being tracked and classified separately.
Of the 145 people who became ill in the United States, 20 were hospitalized, but no one died. Cases occurred in people aged 5 to 86 years, with a median age of 42 years. The cyclosporiasis “season,” or month when the U.S. typically sees a spike in the disease, begins May 1 and runs through the end of August, according to the CDC.
However, these numbers do not include the more than 150 people who have become ill in Michigan since the first case was discovered in the state on June 22. On July 1, the state health department announced that “more than 170 new cases” had been reported, a significant increase from last year’s total of about 50 cases statewide.
The CDC told USA TODAY on July 2 that it had no new data to provide and that its cyclosporiasis infection surveillance dashboard would be updated monthly. The map below reflects the latest available CDC data as of June 16th and additional state-level reporting as of June 30th.
- alaska
- colorado
- connecticut
- florida
- georgia
- illinois
- louisiana
- Massachusetts
- Michigan
- new jersey
- new york
- north carolina
- ohio
- pennsylvania
- tennessee
- texas
- virginia
- wisconsin
How to avoid getting infected with parasites that cause diarrhea
Cyclosporiasis is transmitted through the fecal-oral route, that is, through contact with food, drinks, and surfaces contaminated with infected fecal particles. Usually this means directly consuming affected food or drink, or touching something contaminated and then touching your mouth without washing your hands.
A spike in cyclosporiasis infections is often seen during the warm summer months as infected fecal matter invades fresh summer crops such as basil, raspberries and lettuce, all of which have been linked to past outbreaks in the United States, according to the CDC.
Outbreaks are more common in tropical or subtropical regions of the world such as Central America, South America and Africa, but contaminated or unwashed produce tends to be at the forefront of warm-season surges in the United States, the Michigan Department of Health and Human Services previously told the Detroit Free Press, part of the USA TODAY Network.
Symptoms usually begin about a week after exposure, but symptoms can appear as early as two days or as long as two weeks later.
The infection is treated with antibiotics, and most healthy people can probably fight it off on their own, but the disease can last for months and come back if untreated, according to the CDC. As is often the case, children, older adults, and people with weakened immune systems are more likely to get seriously ill and even die and should contact a health care professional if they become ill.
To prevent getting cysticercosis in the first place, the CDC, Cleveland Clinic, and Michigan Department of Health recommend the following:
- Avoid consuming food or water that may be contaminated with feces. Avoid drinking or cooking with untreated water.
- Wash your hands with soap and water after using the restroom and before, during, and after preparing food.
- Wash all food preparation surfaces, including utensils, cutting boards, and countertops, before and after use.
- Wash and peel vegetables before eating. Give skinned produce such as melons and cucumbers a good rub. Cut out any damaged or bruised parts of fruits and vegetables before cooking and eating.
- Refrigerate cooked fruits and vegetables as soon as possible (within 2 hours).
Contributor: Kristen Jordan Sheamus, Detroit Free Press. Sara Moniuszko, USA TODAY
