Taco Bell is pulling some fresh ingredients from its menu items as a parasite outbreak that causes explosive and watery diarrhea is spreading rapidly across the country.

The fast food chain posted signs at several locations, including in Metro Detroit, informing customers that they are unable to provide a handful of produce items regularly on the menu as health officials investigate a spike in cyclosporiasis cases. Nearly 1,000 people in Michigan have been infected with the illness – the state typically identifies only about 50 cases a year.

Exposure to the Cyclospora parasite leads to cyclosporiasis, a nasty stomach bug often caught through contaminated produce. Cases have spiked over the past week in several states including Michigan, Illinois, Virginia, Ohio, and New York.

“We are currently unable to sell Lettuce, Cilantro, Onion, Pico de Gallo and Guacamole due to a nationwide recall,” the notice outside Taco Bell locations in Detroit reads, WWJ reported.

“We apologize for the inconvenience. Any items ordered that normally come with these items WILL NOT contain them.”

There has not been a specific produce supplier or specific produce type identified as the source of the nationwide outbreak. It was not immediately clear if anyone who ate at a Taco Bell became ill.

The Independent has contacted Taco Bell for more information.

The menu changes come as health officials investigate a spike in cyclosporiasis, a parasite that commonly causes watery diarrhea “with frequent and sometimes explosive bowel movements,” according to the U.S. Centers for Disease Control and Prevention.

The parasite infects the bowels and spreads through feces. Previously, people have become infected after consuming fruit or vegetables that were exposed to feces-contaminated irrigation water.

Previous outbreaks of the illness have been tied to bagged salad mixes, cilantro, basil, snow peas, green onions and raspberries, according to Michigan’s health department.

Fortunately, cyclosporiasis is not usually life-threatening and can typically be treated with antibiotics. There have been no deaths reported that are related to the current outbreak.

Symptoms of cyclosporiasis can include cramping, bloating, nausea, fatigue, weight loss, appetite loss and increased gas. Some patients may also experience vomiting, body aches, diarrhea, headache, low-grade fever and other flu-like symptoms, the CDC said.

While the cases of cyclosporiasis appear to be surging — specifically around southeastern Michigan — it has not been declared a national health emergency.

Thousands of cases of cyclospora illnesses are reported each year in the U.S., and it’s not immediately clear how unusual this year will be, Dianna Blau, the CDC’s acting parasitic diseases branch chief, told the Associated Press.

Health officials say people who have diarrhea that hasn’t gone away on its own within a few days should see a health provider, as they may have been infected by the parasite.

Officials say the best way to avoid an infection is to avoid food or water that may have been contaminated and to thoroughly wash produce before it is eaten.