Michigan's cyclosporiasis outbreak nearly quadruples in a week, reaching over 700 cases, 38 hospitalizations

The Michigan Department of Health and Human Services said Tuesday it has received more than 700 reports of cyclosporiasis since June 22, with 38 of those patients needing hospital treatment.

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

The number of confirmed cases has grown quickly:

• By June 30, there were 170 cases confirmed in Michigan.
• By July 3, there were 400.
• By July 4, there were 572.
• By July 6, there were 680.

Most of the cases have been in southeast Michigan, specifically Monroe County. But multiple cases were soon reported in Jackson, Lenawee, Livingston, Oakland, Shiawassee, Washtenaw and Wayne counties. Michigan usually averages about 50 cases a year.

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

"Without treatment, symptoms can last anywhere from a few days to a month or longer," the CDC says.

The CDC says 17 states have also reported outbreaks since early May, including Illinois, New York and Texas.

What's causing the outbreak?

Health officials said they have not determined the cause or causes of the recent burst in cases, whether that be a supplier, grower or type of produce.

But the Michigan Department of Health and Human Services says previous outbreaks in the United States and Canada were linked to bagged salad mixes, fresh cilantro, fresh basil, raspberries, snow peas and scallions.

Given 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.