Key Points
- More than 3,000 cases have been reported across Michigan and Ohio.
- Michigan has reported more than 2,600 cases.
- Lettuce and salad greens are being investigated as a potential source.
- No specific product, brand, grower or supplier has been identified.
- Cyclospora can cause prolonged watery diarrhea, cramping and bloating.
- The investigation remains ongoing.
A growing outbreak of cyclosporiasis, an intestinal illness caused by the microscopic Cyclospora parasite, has sickened more than 3,000 people in Michigan and Ohio as health officials investigate lettuce and salad greens as a possible source.
Michigan health officials reported 2,640 cases and 44 hospitalizations, while hundreds of additional cases have been reported in neighboring Ohio. Federal health authorities have also recorded confirmed cases across dozens of U.S. states, although officials have not determined whether all of them are connected to the same outbreak.
Are Lettuce and Salad Greens the Source?
Health officials say early information has repeatedly identified lettuce as a common food consumed by people who became ill.
However, investigators have not confirmed lettuce or salad greens as the definitive source, and other foods have not been ruled out.
No specific type of produce, brand, grower or supplier has been publicly identified in connection with the outbreak.
The investigation is complicated because Cyclospora symptoms may not appear until days after exposure, requiring patients to remember what they ate weeks earlier.
What Is Cyclospora?
Cyclospora cayetanensis is a microscopic parasite that can cause an intestinal infection known as cyclosporiasis.
Common symptoms include:
- Frequent watery diarrhea
- Stomach cramps
- Bloating
- Fatigue
- Loss of appetite
- Weight loss
Symptoms can continue for weeks in some people if the infection is not treated.
Unlike many contagious stomach illnesses, cyclosporiasis is generally not transmitted directly from one person to another. Infection is usually associated with consuming contaminated food or water.
Why Is the Outbreak Difficult to Trace?
Finding the source of a Cyclospora outbreak can be particularly difficult because symptoms may develop well after contaminated food was consumed.
By the time a case is confirmed and investigated, patients may struggle to remember exactly what they ate.
Investigators may therefore examine restaurant orders, grocery receipts and shopping records while interviewing people with confirmed infections to identify common foods or locations.
Should People Stop Eating Lettuce?
Health officials have not announced a nationwide recall linked to the outbreak, and no specific lettuce product has been identified as contaminated.
Consumers are being encouraged to follow normal food-safety practices, including thoroughly washing fresh produce and washing hands before preparing or eating food.
Michigan officials have also recommended considering whole heads of lettuce rather than pre-washed bagged greens, removing outer leaves and thoroughly washing the remaining leaves.
The investigation remains ongoing, and health authorities are continuing efforts to identify whether a common food source is responsible for the surge in illnesses.
