The nationwide outbreak of cyclosporiasis — a gastrointestinal illness that causes “explosive diarrhea”— may be far more extensive than federal officials have reported due to Trump administration cuts, experts say.

The foodborne illness, triggered by the cyclospora parasite, has spread to more than two dozen states and is believed to have impacted thousands of people nationwide, making it one of the worst outbreaks in recent years.

Yet a precise case count has proved difficult to pin down after the parasite was dropped from a key U.S. Centers for Disease Control and Prevention tracking program last year.

Last summer, the CDC scaled back its Foodborne Diseases Active Surveillance Network — the primary system for monitoring these types of illnesses known as FoodNet — to track just two pathogens: salmonella and E. coli. Prior to the change, the network also monitored six other pathogens, including cyclospora. As a result, one expert warned: “We have a lot less information to work with.”

The reduction in monitoring appears to be reflected in the latest CDC data on cyclosporiasis. As of July 9, the CDC reports there are 843 confirmed cases across 31 states. Data provided by Michigan health officials Tuesday reveals there are 3,309 cases in that state alone — nearly four times the CDC’s national tally.

An increase in cases have also been reported in Illinois, Virginia, Ohio, and New York. On Friday, officials in New York reported about 470 cases statewide, according to CBS News. On Monday, the Illinois Department of Public Health announced at least 194 confirmed or probable cases, according to WTTW.

The CDC’s website acknowledged that its count may be low, stating the agency is “aware of more than 1,500 cases that require further analysis to confirm the illness as domestically acquired cyclosporiasis.” The agency also notes it has a six-week “reporting lag between illness onset and case reporting.”

The Independent has contacted the CDC for further comment.

The CDC’s decision last July to remove cyclospora from FoodNet reportedly came down to funding. In a CDC statement obtained by NBC News, officials wrote: “Funding has not kept pace with the resources required to maintain the continuation of FoodNet surveillance for all eight pathogens.”

The pathogen-monitoring cuts took place amid special government employee Elon Musk’s DOGE initiative to slash federal budgets and workforces, including at the CDC. Over the past year and a half, about 25 percent of CDC staff were pushed out or left, according to Bloomberg.

When FoodNet was scaled back, food safety experts warned that the move could make it harder to track and respond to cases of foodborne illness.

“Essentially, CDC is backing off on one of their best surveillance systems,” Dr. J. Glenn Morris, the director of the University of Florida’s Emerging Pathogens Institute, told NBC News last July.

Amid this year’s cyclosporiasis outbreak, experts are sounding a similar alarm.

“We have a lot less information to work with,” Kalmia Kniel, a professor of microbial food safety at the University of Delaware, told USA Today this week. “I think we’re seeing some of the effects of that now.”

“An incredibly important prevention method is to get those surveillance systems back up and running,” Jill Roberts, professor of environmental health biology at the University of South Florida College of Public Health, told WUSF. “When we were able to detect these things fast, we can keep them out of the food systems.”

“We have to be reactive instead of proactive,” she added.

Based on available data, the latest cyclosporiasis outbreak appears to be the worst in recent years. There are only a few documented outbreaks surpassing 1,000 cases over the past two decades, according to CNBC.

Cyclospora is transmitted when people consume food or water contaminated with fecal matter, according to the CDC. Exposure to the cyclospora parasite leads to cyclosporiasis, an infection with symptoms including “watery diarrhea” and “explosive bowel movements,” as well as fatigue, stomach cramps, bloating, nausea, vomiting and a low-grade fever. It is rarely life-threatening.

On Tuesday, The Washington Post reported that state and federal officials are examining whether the rash of cases is connected to the fast-food chain Taco Bell.

Signs posted at several Taco Bell locations in Michigan last week warned customers that the restaurants were “currently unable to sell Lettuce, Cilantro Onion, Pico de Gallo, and Guacamole due to a nationwide recall.” State health officials believe the illness may have been transmitted via lettuce.

The Independent has contacted Taco Bell for comment.