(NewsNation) — Michigan’s Department of Health and Human Services is pointing to lettuce and salad greens as the possible source of a stomach parasite behind a nationwide outbreak of severe diarrhea.

State officials sent out a release Monday detailing their preliminary investigation into the cyclosporiasis outbreak. The possible source was identified after the health department conducted more than 1,000 interviews with people who tested positive for the cyclospora parasite.

“Early information has shown lettuce as a common product that regularly comes up during the investigation,” said Dr. Natasha Bagdasarian, chief medical executive of MDHHS.

The department made it clear that other food items cannot be completely ruled out, nor has a specific type of produce, grower, or supplier been identified as the source.

As of July 9, the Centers for Disease Control and Prevention has reported 843 cases across the U.S. However, Michigan’s health department reports 2,640 cases as of July 13. The CDC says it is aware of the inconsistencies and is working closely with states to better reflect the data.

Currently, Michigan and New York have the most cases of cyclosporiasis, followed by Texas, North Carolina, Kentucky, Illinois, and New Jersey. Cases have also been reported in Alaska, Alabama, Arkansas, Colorado, Connecticut, California, Florida, Georgia, Indiana, Iowa, Kansas, Massachusetts, Maryland, Maine, New Hampshire, New Mexico, Rhode Island, South Carolina, North Dakota, Nebraska, Nevada, Ohio, Oklahoma, Oregon, Tennessee, Virginia, West Virginia, Wisconsin and Utah.

What is the ‘explosive’ diarrhea parasite cyclosporiasis?

Cyclosporiasis is a type of food poisoning caused by a parasite, according to the CDC. People usually become infected from consuming food or water contaminated with feces. Symptoms usually occur within two to 14 days after ingestion.

While cyclosporiasis is not usually life-threatening, people can experience severe symptoms, including cramps, nausea, fatigue and vomiting. The most commonly reported symptom is “watery diarrhea with frequent, sometimes explosive, bowel movements,” according to the agency. Other common symptoms include loss of appetite, weight loss, increased gas, body aches, headache, low-grade fever and other flu-like symptoms.

If it’s not treated with antibiotics, it can last anywhere from a few days to over a month. Symptoms can also go away and return multiple times.

The health agency noted there’s a higher risk of infection when living in or traveling to tropical or subtropical regions, where the parasite is more common.

Protecting yourself from cyclosporiasis

If you plan to prepare or eat raw foods, the CDC recommends taking the following steps to reduce the risk of exposure:

• Wash your hands with soap and water before and after handling or preparing raw fruits and vegetables.
• Thoroughly wash all fresh produce, herbs, fruits and vegetables before eating, cutting, and cooking.
• Scrub firm fruits and vegetables, such as melons and cucumbers, with a clean produce brush.
• Cut away any damaged or bruised areas on fruits and vegetables before preparing and eating.
• Refrigerate cut, peeled, or cooked fruits and vegetables as soon as possible, preferably within two hours.
• If cooking raw foods, make sure they reach 158°F or higher to kill cyclospora parasites.