The US Centers for Disease Control and Prevention (CDC) has identified lettuce from Mexico served at Taco Bell locations across five states as a source of a widespread cyclosporiasis outbreak, which has caused explosive diarrhea in hundreds of people. Michigan has reported nearly 1,000 cases, making it the largest outbreak in the state's history.
Outbreak Details and Source
Michigan typically sees about 50 cyclosporiasis cases annually, but the current outbreak has surged to almost 1,000 cases. Ohio has also reported 177 cases as of July 2. The CDC has recorded 145 cases across 17 states as of June 16, but this figure likely underestimates the true number due to reporting lags. Late Thursday, the CDC identified shredded iceberg lettuce from a single Mexican supplier used by Taco Bell in Indiana, Kentucky, Michigan, Ohio, and West Virginia as the source. The supplier was not named, but Taco Bell has stopped using lettuce from that supplier.
What Is Cyclosporiasis?
Cyclosporiasis is a gastrointestinal illness caused by the parasite Cyclospora cayetanensis, which spreads through raw produce or water contaminated with human feces. In the US, it is seasonal, with outbreaks typically occurring from May to August. Past outbreaks have been linked to contaminated basil, cilantro, berries, and spinach. Symptoms include watery diarrhea with frequent and sometimes explosive bowel movements, cramps, nausea, fatigue, loss of appetite, low-grade fever, and vomiting. Symptoms can last from several days to over a month. The average time from ingestion to symptoms is about one week. The illness is rarely life-threatening, and most people recover without treatment, though antibiotics are effective.
Comparison to Previous Outbreaks
Cyclosporiasis outbreaks in the US have been linked to imported produce contaminated by feces-tainted irrigation water. In 2022, a Florida outbreak from packaged salad kits sickened hundreds. Only a handful of outbreaks have exceeded 1,000 cases in the last 20 years, including a 1996 outbreak from Guatemalan raspberries (1,500 cases) and a 2019 outbreak from Mexican basil (2,400 cases across the US and Canada).
Protection and Recommendations
To prevent infection, the CDC advises avoiding potentially contaminated food or water. Thoroughly washing fresh produce may not eliminate Cyclospora, especially on items with nooks and crannies like raspberries, lettuce, and cilantro. Health officials recommend purchasing whole heads of lettuce instead of pre-washed bags, removing outer leaves, and washing under running water. Cooking produce can kill the parasite.
