Health authorities in Michigan are pointing to lettuce or leafy green vegetables as the likely source of the cyclosporiasis outbreak that has already resulted in nearly 3,000 confirmed cases across 31 states, including Florida, with at least 86 hospitalizations nationwide.
Dr. Natasha Bagdasarian, executive medical director of Michigan, specified that "preliminary information indicates that lettuce is a common product that frequently appears during the investigation."
The authorities clarified, however, that there is still not enough evidence to pinpoint a specific type of lettuce, a producer, or a supplier, and that other foods are also not being ruled out.
Michigan, epicenter of the outbreak
The state of Michigan accounts for the majority of infections, with 2,640 confirmed cases and 44 hospitalizations.
Ohio ranks second, with 361 cases since June 1 and at least 46 people hospitalized.
Florida has reported at least 60 cases across 25 counties, with the highest numbers in Lee, Miami-Dade, and Broward.
The Centers for Disease Control and Prevention (CDC) report a national count of 843 confirmed cases since May 1, a number lower than that of the states because federal analysis takes more time.
The agency acknowledged that the total number could be higher, as symptoms may take up to a week to manifest.
The outbreak of 2026 quadruples the cases reported during the same period of the previous year.
Taco Bell under scrutiny by authorities
A revelation this Tuesday added a new dimension to the investigation: according to The Washington Post, citing two individuals familiar with the case, federal and state authorities are examining whether Taco Bell restaurants played any role in the spread of the parasite.
As a precautionary measure, the chain removed fresh ingredients such as lettuce, cilantro, onion, pico de gallo, and guacamole from some locations—primarily in southeastern Michigan, in the counties of Wayne, Oakland, Monroe, and Washtenaw.
The company stated that it does not believe its ingredients are linked to the outbreak. The CDC has not publicly identified Taco Bell as the source of the infection.
Symptoms, treatment, and recommendations
Cycsporiasis is not transmitted from person to person; infection occurs when consuming fresh foods or water contaminated with human feces.
The symptoms—intense watery diarrhea, abdominal cramps, nausea, and fatigue—can appear between one and 14 days after exposure and can last for weeks.
The ages of the affected individuals range from five to 88 years, with a median age of 44, and 59% are women.
The treatment consists of the antibiotic combination trimethoprim-sulfamethoxazole (Bactrim or Septra) for seven to ten days.
While the investigation continues, Michigan authorities recommend avoiding prepackaged salads, opting for whole lettuces that are thoroughly washed, removing the outer leaves, and cooking vegetables whenever possible.
Why is it so difficult to trace this parasite?
The Cyclospora cayetanensis is notoriously difficult to trace through genetic analysis, unlike bacteria such as E. coli or Salmonella.
Jennifer McEntire, microbiologist and executive director of Food Safety Strategies, explained it this way: “It’s like reading a children’s book compared to reading 'War and Peace', with Cyclospora being the 'War and Peace'.”
This difficulty is compounded by an institutional factor: in July 2025, the CDC reduced the FoodNet surveillance program from actively monitoring eight pathogens to only two mandatory ones - Salmonella and E. coli - eliminating 75% of active surveillance on Cyclospora.
Dr. Robert Redfield, former director of the CDC, criticized that decision: "I don't believe it is in the interest of our country to cut these programs. Surveillance is essential for early detection."
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