Michigan health officials issue new guidance as cyclosporiasis cases climb to 572

The Michigan Department of Health and Human Services said the number of confirmed cyclosporiasis infections in the state rose to 572 by July 4, up sharply from 170 a few days earlier. The outbreak is concentrated in Monroe, Lenawee, Washtenaw, Wayne, Shiawassee, Jackson, Oakland and Livingston counties, and officials are still investigating the source.

Cyclosporiasis is an intestinal infection caused by the Cyclospora parasite, which can produce watery, sometimes explosive diarrhea lasting from several days to more than a month. Symptoms typically appear about a week after exposure, though the incubation period can vary from two days to two weeks.

The department released new food-handling guidance on July 6, emphasizing thorough washing and cooking of certain raw produce. For lettuce and other leafy greens, officials advise buying whole heads, discarding the outer layers and rinsing inner leaves under running water, with cooking being the safest option. Cilantro, basil and green onions should be washed carefully and cooked when possible. Raspberries, whose uneven surface makes cleaning difficult, are recommended to be cooked or substituted with frozen berries, while snow peas should be rinsed and rubbed before cooking.

"The recommendations are especially important for individuals at higher risk of dehydration or with weakened immune systems, such as chemotherapy patients, organ-transplant recipients, infants, young children and the elderly," the department said.

General food-safety advice includes cooking foods to at least 158 °F (70 °C) to kill the parasite and washing all fresh produce under clean running water, even if it will be peeled later.