Michigan sees thousands of cyclospora cases linked to Taco Bell lettuce, health officials advise testing and hydration

More than 5,000 Michigan residents have been diagnosed with cyclosporiasis, a diarrheal illness caused by the cyclospora parasite, after investigations linked the outbreak to shredded iceberg lettuce supplied to Taco Bell. The U.S. Centers for Disease Control and Prevention and the Food and Drug Administration confirmed the contaminated produce, prompting Taylor Fresh Foods to withdraw its iceberg lettuce from the U.S. market and Taco Bell to remove the ingredient from its supply chain.

Patients, including a 67-year-old former nurse who required IV fluids and potassium supplements, have reported severe dehydration and prolonged watery diarrhea lasting weeks. Health officials note that symptoms can resemble other gastrointestinal bugs, leading to underreporting.

"Any persistent chronic diarrhea — it comes and goes, it lasts for more than a week — for anyone, I think that’s when you’d go to get tested," said Dr. Peter Chin-Hong of UCSF.

"If you’re having diarrhea and you’re just not feeling well, I think reaching out to your primary care physician is completely appropriate," added Dr. Timothy Brewer of UCLA.

Testing involves stool samples analyzed by PCR or microscopy, often requiring multiple specimens. The first-line treatment is trimethoprim-sulfamethoxazole; alternatives such as ciprofloxacin or nitazoxanide are used when allergies or side-effects preclude the primary drug. Patients are urged to maintain fluid intake with oral rehydration solutions and a bland diet, and to seek medical care if dehydration signs like skin tenting, confusion, or dark urine appear.

Public health agencies will contact confirmed cases to trace exposures, as cyclosporiasis is not spread person-to-person. Officials continue to monitor the outbreak, which has been reported in 34 states since early May.