Michigan health officials are investigating a major outbreak of cyclosporiasis after confirmed infections rose to 2,640 cases as of July 13. The number is far higher than the state’s usual annual total of 40 to 50 cases, making it one of the largest outbreaks ever reported in Michigan.
Although investigators have not identified a specific food product, lettuce and salad greens have emerged as the leading suspected source based on interviews with infected patients.
Lettuce emerges as the main suspected source
The Michigan Department of Health and Human Services (MDHHS) said investigators have interviewed more than 1,000 people who became ill during the outbreak.
According to officials, many of those patients reported eating lettuce before developing symptoms. However, authorities have not linked the outbreak to any particular brand, farm, supplier, or retailer.
Health experts also clarified that other food items have not been ruled out. Therefore, the investigation continues as officials work to identify the exact source.
Dr. Natasha Bagdasarian, Michigan’s Chief Medical Executive, said the department wanted residents to know the latest findings even though the investigation is not yet complete.
She explained that sharing the information now would help families take steps to reduce their risk.
Health department issues safety advice
As a precaution, Michigan health officials have advised residents to make a few temporary changes when buying and preparing leafy vegetables.
They recommend:
- Buy whole heads of lettuce instead of pre-washed bagged salads.
- Remove and throw away the outer two or three leaves.
- Wash the remaining leaves thoroughly under running water.
- Cook leafy greens whenever possible.
Officials also noted that heating food to 158°F (70°C) can kill the Cyclospora cayetanensis parasite.
What is Cyclospora?
Cyclospora is a microscopic parasite that causes cyclosporiasis, a foodborne illness usually spread through contaminated food or water.
People infected with the parasite commonly experience:
- Watery diarrhea
- Stomach cramps
- Nausea
- Loss of appetite
- Fatigue
Symptoms can last for several days or even weeks if left untreated.
No link found with swimming pools or lakes
Health officials stressed that there is no evidence connecting the outbreak to swimming pools, lakes, or other recreational water.
Instead, investigators continue to focus on contaminated food as the most likely cause of the infections.
What to do if you have symptoms
Anyone who develops prolonged watery diarrhea or other symptoms should contact a healthcare provider as soon as possible.
Doctors may recommend testing specifically for Cyclospora, since standard stool tests often do not detect the parasite without a targeted request.
The health department said early diagnosis and treatment can help reduce the severity and duration of the illness while the investigation continues.