Health officials in Michigan have identified lettuce or leafy greens as the likely source of a cyclospora outbreak that has already resulted in nearly 3,000 confirmed cases across 31 states, including Florida. The outbreak has led to at least 86 hospitalizations nationwide.
Dr. Natasha Bagdasarian, Michigan's Chief Medical Executive, indicated that "preliminary information suggests that lettuce is a common product that frequently appears during the investigation."
However, authorities noted that there is still insufficient evidence to pinpoint a specific type of lettuce, producer, or supplier, and other food sources have not been ruled out.
Michigan's Role as Epicenter
Michigan is at the heart of the outbreak, with 2,640 confirmed cases and 44 hospitalizations. Ohio follows with 361 cases reported since June 1, with at least 46 individuals hospitalized.
In Florida, at least 60 cases have been reported across 25 counties, with the highest numbers in Lee, Miami-Dade, and Broward.
The Centers for Disease Control and Prevention (CDC) have recorded a national tally of 843 confirmed cases since May 1. This number is lower than state counts as federal analysis requires more time. The agency acknowledges that the total number of cases could be higher, given that symptoms may take up to a week to appear.
The 2026 outbreak has quadrupled the cases recorded during the same period last year.
Taco Bell Under Investigation
On Tuesday, new revelations added a layer to the investigation: The Washington Post reported that federal and state authorities are examining whether Taco Bell restaurants played a role in spreading the parasite, citing two individuals familiar with the case.
As a precautionary measure, the chain has removed fresh ingredients such as lettuce, cilantro, onions, pico de gallo, and guacamole from some outlets, mainly in southeastern Michigan's Wayne, Oakland, Monroe, and Washtenaw counties.
The company stated that it does not believe its ingredients are linked to the outbreak. The CDC has not publicly identified Taco Bell as a source of infection.
Understanding Cyclospora: Symptoms, Treatment, and Recommendations
Cyclospora is not transmitted from person to person; infection occurs by consuming fresh produce or water contaminated with human feces. Symptoms include severe watery diarrhea, abdominal cramps, nausea, and fatigue, emerging between one to 14 days after exposure and potentially lasting for weeks.
The age range of those affected is between five and 88 years, with a median age of 44 years, and 59% are women.
The recommended treatment is a combination antibiotic, trimethoprim-sulfamethoxazole (Bactrim or Septra), for seven to ten days. As the investigation continues, Michigan authorities advise avoiding prepackaged salads, choosing whole, well-washed lettuce, removing outer leaves, and cooking vegetables whenever possible.
The Challenge of Tracing Cyclospora
Tracing Cyclospora cayetanensis is notoriously challenging through genetic analysis, unlike bacteria such as E. coli or Salmonella. Jennifer McEntire, microbiologist and CEO of Food Safety Strategies, explained, "It's like reading a children's book compared to reading 'War and Peace,' with Cyclospora being 'War and Peace.'"
This difficulty is compounded by an institutional factor: in July 2025, the CDC reduced the FoodNet surveillance program from monitoring eight pathogens to just two mandatory ones—Salmonella and E. coli—eliminating 75% of active surveillance on Cyclospora.
Dr. Robert Redfield, former CDC director, criticized this decision: "I don't believe it's in our country's interest to cut these programs. Surveillance is crucial for early detection."
Frequently Asked Questions about the Cyclospora Outbreak
What is causing the cyclospora outbreak in the United States?
The likely source of the cyclospora outbreak is contaminated lettuce or leafy greens, although the exact type of lettuce, producer, or supplier has not been identified.
How is cyclospora transmitted?
Cyclospora is transmitted by consuming fresh produce or water contaminated with human feces. It is not spread from person to person.
What are the symptoms and treatment for cyclospora infection?
Symptoms include severe watery diarrhea, abdominal cramps, nausea, and fatigue. The recommended treatment is a combination antibiotic, trimethoprim-sulfamethoxazole, for seven to ten days.