The Centers for Disease Control and Prevention has confirmed more than 800 cases of cyclosporiasis, a gastrointestinal illness that causes extreme diarrhea, across more than half of U.S. states. The grand total appears set to continue climbing as the agency is investigating more than 1,500 likely new cases.

The illness is cause by the cyclospora parasite, which enters the body through contaminated produce. If you’re unlucky enough to ingest it, you may get stuck with weeks of watery diarrhea as well as “frequent and sometimes explosive bowel movements,” according to the CDC.

The exact source of this massive outbreak isn’t yet known, but in the past cyclospora has largely been found on fresh fruits and vegetables that were contaminated by irrigation water tainted with feces.

Historically, the most commonly contaminated foods were raspberries, basil, cilantro, green onions, snow peas, lettuce, mesclun and salad mixes. A study reviewing outbreaks since the 1990s found cyclospora may also have contaminated blackberries, watercress, mango, and vegetable trays.

An investigation of the 2026 outbreak is ongoing, but health officials in Michigan – a state hit especially hard by the parasite – are starting to suspect lettuce or salad greens may be to blame.

“I’m annoyed at cyclospora,” said infectious disease expert Dr. Bruce Hirsch in an interview with Nexstar’s WPIX. “Cyclospora is contaminating the most healthful, delicious, seasonal foods there are.”

Frozen or cooked foods – including things like frozen berries and vegetables – are in the clear.

“To date, no commercially frozen produce, cooked foods or peeled fruit have been associated with cyclosporiasis infection,” the study said.

How is cyclosporiasis treated?

The infection can be treated with antibiotics. If a person is experiencing persistent diarrhea, they should consider seeking medical attention given the current outbreak.

A stool test will be necessary to diagnose it as a case of cyclosporiasis.

Gastroenterologist Dr. Ariel Malamud told KTLA symptoms often start five to seven days after exposure.

How can you safely consume fruits and vegetables during this outbreak?

Basic hygiene goes a long way here. People should wash hands with soap and water after using the bathroom and before handling food, said Dr. Erika Noel, an assistant professor at Hawaii’s medical school and a pediatrician on the island of Kauai.

Alcohol-based hand sanitizers don’t kill cyclospora, but soap and water are highly effective at killing or removing the parasite from hands.

Noel also has some tips for washing produce: When washing items like cilantro and basil, separate the leaves. For green onions, cut off the roots, remove the outer layer and run them under water while rubbing the surface.

Research shows that washing fruits and vegetables in vinegar can be helpful. Vinegar won’t kill the parasite but can help remove it. Noel recommends submerging produce in a bowl filled with three parts water and one part vinegar and swishing it around for a few minutes. Using a salad spinner to rinse with water can help get rid of the vinegary taste.

If using pre-mixed salads that have labels that indicated the items have been washed, it’s best to wash them again in water and vinegar. Or, instead of purchasing pre-mixed salad and washing individual leaves, opt for a head of lettuce and remove the outer layer.

Anything with tight crevices or fragile skin can be challenging to clean, like broccoli and cauliflower. Because berries are challenging, Noel recommends cooking them in pies or making jam instead of eating them raw.

Anything grown underground and covered in thick dirt are also tough to clean, such as root vegetables like carrots, potatoes and radishes.

Peel fruits and vegetables as much as possible. For melons, scrub the outside before cutting through as the knife can carry germs from the rind into the fruit inside.

Cooking produce to an internal temperature of 158 degrees Fahrenheit or higher will also kill cyclospora.

Don’t forget to wash cutting boards and countertops.

Source: https://www.wfla.com/news/national/

The Associated Press contributed to this report.