Rumors that U.S. President Donald Trump's administration cut public health tracking of an intestinal parasite that causes "explosive diarrhea" circulated in July 2026.

Social media users claimed the Centers for Disease Control and Prevention altered a longstanding policy in 2025 that supported surveillance of cyclospora, a parasite that causes cyclosporiasis, a disease the CDC described as an infection of the small intestine that "usually causes watery diarrhea with frequent and sometimes explosive bowel movements." The infection is caused by the consumption of food or water contaminated by fecal matter.

The rumor circulated during an outbreak of thousands of cases of cyclosporiasis across the country.

In sum, the claim was true.

The CDC's website about FoodNet (archived) — described as a collaboration between the CDC, the Department of Agriculture, the Food and Drug Administration and 10 state health departments — that traditionally tracked infections from eight different pathogens, showed that as of July 1, 2025, reporting for all pathogens outside of salmonella and E. coli had been made optional.

Prior to this change, surveillance of cyclospora had been mandatory since 1997.

A disclaimer on the FoodNet website said that despite the change, FoodNet's purpose was "not designed to detect outbreaks of foodborne illness" and that "no recent changes have been made to how CDC and our federal, state, and local partners detect and investigate outbreaks through existing epidemiologic or laboratory systems."

Multiple media outlets reported the change in policy in August and September 2025, including The Associated Press, NBC News, The New York Times, Ars Technica and food-industry publication Food Safety News.

During the 2026 outbreak, the CDC website about surveillance of cyclospora (archived) stated:

Since May 1, 2026, CDC has received reports of 1,645 confirmed domestic cases of cyclosporiasis and is aware of more than 5,100 cases that require further analysis to confirm the illness as domestically acquired cyclosporiasis. So far this year, multiple states have reported an increase in cases compared to the same period in 2025.

History of cyclospora

A 2023 CDC report, embedded below, described cyclospora as a "newly identified human gastrointestinal pathogen" discovered between 1993 and 1994.

"There remain significant knowledge and data gaps that hamper the implementation of effective measures to prevent the contamination of produce" by cyclospora, the report said, adding that while cyclosporiasis was "previously associated with international travel or consumption of contaminated imported foods," there had been an increase in cases associated with U.S.-grown produce.

The report showed the largest foodborne outbreak prior to 2026 was in 1996, when 1,465 cases were linked to raspberries from a Guatemalan farm.

The report said the first U.S-originated outbreak was linked to basil in 1997, the year FoodNet started reporting on cyclospora.

Snopes reached out to the Trump administration and the CDC for comment on the outbreak and further data on whether the spread could be definitively linked to the changes in the FoodNet program. We will update this article if we learn more.