Michigan's cyclosporiasis outbreak expands to more than 3,700 cases

Michigan health officials say the state's cyclosporiasis outbreak has now grown to more than 3,700 cases. 

As of July 15, the Michigan Department of Health and Human Services has received 3,762 reports since June 22. Health officials say 44 people have been hospitalized, as of July 9. 

Cyclospora cayetanensis is a parasite that causes the diarrheal illness cyclosporiasis. The Centers for Disease Control and Prevention says the most common symptoms associated with the illness are frequent watery diarrhea, loss of appetite, bloating, nausea and fatigue. Some people may also experience body aches, headache or vomiting.  

"In Michigan alone, with more than 3,300 cases, this already makes this likely the largest cyclosporiasis outbreak in U.S. history," said Dr. Natasha Bagdasarian, MDHHS chief medical executive. 

The outbreak of the gastrointestinal illness was first reported in Monroe County in June, when the Monroe County Health Department said it was investigating a cluster of cases. 

Most cases have been concentrated in Southeast Michigan, with more than 100 reported in each of Monroe, Wayne, Washtenaw, Livingston, Oakland, and Lenawee counties. As of July 13, cases have been confirmed in 55 Michigan counties, with Wayne County reporting 339 cases. 

On average, Michigan has around 50 cases of cyclosporiasis each year, according to MDHHS. 

As of July 14, at least 34 states have reported cases, including Illinois, New York, and Texas, according to the CDC.   

What's causing the outbreak?

On July 13, Michigan health officials said that testing showed lettuce or salad greens as a potential source of the cyclosporiasis outbreak. 

MDHHS says other food items have not been entirely ruled out as a source, and officials have not identified a specific grower or supplier. 

"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," Bagdasarian said. "Early information has shown lettuce as a common product that regularly comes up during the investigation." 

Michigan health officials have more than 1,000 people who have been sickened, according to Bagdasarian, with questions focused on where people have eaten, which restaurants they've been to, including any fast food chains, and which menu items they've ordered. 

According to MDHHS, previous outbreaks in the U.S. and Canada were linked to bagged salad mixes, fresh cilantro, fresh basil, raspberries, snow peas and scallions.

Considering the trends, state health officials recommend that restaurants and commercial kitchens in Southeast Michigan take additional precautions with fresh produce, including washing it under clean running water and cooking it when possible.

Tips to prevent cyclosporiasis

Health officials shared the following tips for avoiding the illness:

• Wash all fruits and vegetables thoroughly, under running water, before cutting, cooking or eating.
• Scrub firm fruits and vegetables, such as melons and cucumbers, with a produce brush when cleaning.
• Cut away any damaged or bruised areas of produce before preparing and eating.
• Refrigerate any cut, peeled or cooked produce within two hours of preparing it.