Parasite Outbreak Surges

A rapidly expanding outbreak of cyclosporiasis has sickened thousands of people across several Midwestern states, prompting a major lettuce recall and an intensive investigation by federal and state health agencies.

Cyclosporiasis is an intestinal illness caused by ‘Cyclospora cayetanensis ', a microscopic parasite transmitted through contaminated food or water. The infection commonly causes prolonged watery diarrhea, along with stomach cramps, nausea, bloating, fatigue, loss of appetite and weight loss.

Symptoms generally begin about one week after exposure but may appear anywhere from two days to two weeks later. Without treatment, the illness can persist for weeks and may disappear temporarily before returning.

Cases normally increase during the spring and summer, but this year’s numbers are unusually high. Federal health officials have been investigating several clusters, including a large multistate outbreak affecting Indiana, Kentucky, Michigan, Ohio and West Virginia.

The Centers for Disease Control and Prevention has linked approximately 1,644 confirmed illnesses to the five-state outbreak. However, figures released by individual states are considerably higher because they include reported or suspected cases still being reviewed and illnesses that may not ultimately be connected to the same food source.

Michigan has reported the largest number, with 6,571 cyclosporiasis cases recorded during the investigation period as of July 21. At least 102 patients had been hospitalized as of July 16. Michigan health officials cautioned that they cannot confirm that every reported illness came from the same exposure, although the concentrated and sudden rise strongly suggests that most are associated with the outbreak.

Indiana reported 511 cases as of July 21, with patients ranging in age from 8 to 91. Additional state totals cited during the investigation include more than 1,200 cases in Ohio and nearly 200 each in Kentucky and West Virginia. Those figures remain subject to revision as laboratories confirm infections and investigators interview patients.

A federal traceback investigation identified Taylor Farms de Mexico as the supplier of shredded iceberg lettuce served at Taco Bell restaurants where some patients reported eating before becoming ill. Taylor Farms subsequently removed all iceberg lettuce sourced from central Mexico from the U.S. market and recalled affected retail and food-service products.

Recalled items include certain Marketside iceberg salads and shredded lettuce sold at Walmart with use-by dates ranging from July 18 through August 3.

Although federal officials have said the recall has helped bring the outbreak under control, additional illnesses may still be reported because symptoms can take up to two weeks to develop and diagnosis often requires specialized testing.

Consumers should check refrigerators for recalled lettuce and discard or return affected products. Anyone experiencing persistent watery diarrhea, especially after eating recalled lettuce or food from an affected restaurant, should contact a health care provider.

Cyclosporiasis can usually be treated with prescription antibiotics, while dehydration may require additional medical care.