While there are typically around 50 reported cases of a parasitic virus called cyclosporiasis, there have already been over 170 cases reported in 2026. The State of Michigan Department of Health and Human Services reports 21 cases in Washtenaw County as of Tuesday, June 30, 2026.
According to the Centers for Disease Control, cyclosporiasis is an intestinal illness caused by a microscopic parasite called Cyclospora cayetanensis, also known as Cyclospora.
This parasite is spread when ingested food has touched and been contaminated with feces. The parasite usually takes 1-2 weeks to become infectious, so person-to-person transmission is unlikely. The most common way for this illness to spread in Michigan is through fresh produce.
While the illness is not usually fatal, symptoms include watery stool, frequent diarrhea, loss of appetite, nausea, vomiting, and abdominal cramping and pain. Symptoms can begin 2-14 days after infection and last for weeks if not treated. Symptoms can be vastly and easily improved with antibiotics.
The Washtenaw County Health Department announced on a Facebook post that public health officials are looking into the sudden outbreak of cyclosporiasis in southeast Michigan, including Washtenaw County.
The Health Department urged residents to wash their hands and produce and to contact a health provider if experiencing sudden and persistent diarrhea.
The State of Michigan Department of Health and Human Services urges Michiganders to wash all produce, including scrubbing firm fruit such melons, cutting off bruised or discolored parts of fruits and vegetables, and to refrigerate all cut, peeled or cooked produce as soon as possible.
