Cyclospora Outbreak Reaches Over 7,000 Cases Across 34 States

More than 7,000 cases of cyclosporiasis have been confirmed or are under investigation across 34 states since May 1, according to the Centers for Disease Control and Prevention. Michigan and Ohio account for more than 3,000 of those cases, with additional reports in West Virginia and Kentucky.

Health officials in Michigan have identified lettuce or salad greens as a possible source, though other foods have not been ruled out. Investigators at the CDC are collecting information to trace the contamination through the food supply chain.

Jason Reese, a food safety expert and co-founder of Wagner Reese LLP, said the parasite spreads through contaminated fecal matter in food or water and is not transmitted person to person. He noted that contamination typically occurs at the farm or during processing, often through tainted irrigation water or poor worker hygiene.

Reese added that symptoms can take up to a week to appear, making it difficult for individuals to link illness to a specific meal. He listed bagged salads, herbs such as cilantro and basil, green onions, leafy greens, snow peas, and raspberries as higher-risk items.

Roberts, a microbiologist and professor at the University of South Florida College of Public Health, described four parasites commonly associated with produce, water, and undercooked meat. Cyclospora is most often found in imported produce and has previously been linked to basil, cilantro, snow peas, and berries.

Cryptosporidium spreads through contaminated water and is resistant to chlorine, requiring filtration for removal. It caused the largest waterborne disease outbreak in U.S. history in Milwaukee in 1993. Giardia spreads similarly through water and produce washed with contaminated water and is also chlorine-resistant.

Toxoplasma gondii is primarily linked to undercooked meat and can cause serious infections in immunocompromised individuals and pregnant women.