The cyclosporiasis outbreaks continues to grow with 2,640 cases reported as of Monday, July 13. The Michigan Department of Health and Human Services (MDHHS) is continuing to investigate an outbreak. Results are suggesting lettuce or salad greens may be a potential source, but other food items have not been ruled out. No specific type of produce, grower or supplier has yet been identified as the source.
“Although we do not have a definite product identified as the source of the outbreak, we want to let Michiganders know what we have learned so far so they can take steps to protect their families,” said Dr. Natasha Bagdasarian, chief medical executive. “Early information has shown lettuce as a common product that regularly comes up during the investigation. We will continue to provide updates as we learn more.”
It will take time for agencies to complete their investigation given the extent of the outbreak, the one to two week incubation period before symptoms develop after exposure, and complex food distribution networks across the state and country.
MDHHS recommends the following lettuce-specific safety measures:
- Purchase whole heads: Buy whole heads of lettuce rather than pre-washed, bagged lettuce or pre-mixed salad kits.
- Discard outer layers: Before preparation, throw away the outer two to three layers of leaves.
- Wash inner leaves: Thoroughly wash the remaining inner leaves under clean running water.
- Prioritize cooking: For any greens that can be cooked, cooking to a temperature of at least 158 F (70 C) is the safest option, as the parasite is resistant to routine chemical disinfection and washing alone cannot guarantee its removal.
General rules to reduce risk:
- Cook when possible. Heating food to 158 F (70 C) or higher kills cyclospora.
- Peel produce. Peeling is highly effective for food items with removable skin as the parasite sits on the outer surface.
- Wash all fresh produce. Wash under clean running water, even if you plan to peel it. “Pre-washed” does not guarantee safety and rewashing bagged lettuce is unlikely to remove cyclospora. While washing alone may not fully eliminate cyclospora, it enhances protection when combined with cooking or peeling.
These recommendations are particularly important for people who have a higher risk of dehydration or weakened immune systems such as patients on chemotherapy, organ transplant recipients, infants and young children and elderly people.
Recreational water exposure, such as swimming in lakes, is not a recognized risk factor for cyclosporiasis and there’s currently no evidence linking recreational water activities to the outbreak. Foodborne exposure remains the focus of the investigation.
If you do become ill, contact your health provider. Cyclosporiasis is treated with antibiotics along with rest and drinking plenty of fluids to maintain hydration.
For more information, visit the MDHHS Infectious Disease Outbreaks web page.
Additional information is also available at About Cyclosporiasis | Cyclosporiasis | CDC.
