Michigan has recorded 681 cases of cyclosporiasis since June 22. The Michigan Department of Health and Human Services described the count as an unusual number compared to the state's typical annual average of approximately 50 cases. Investigations are active to identify the cause of outbreaks in both Michigan and Ohio.

Cyclosporiasis is an intestinal disease caused by the microscopic parasite Cyclospora cayetanensis, which is generally not fatal. The illness is transmitted through the ingestion of food or water contaminated with human feces. Common sources include raw agricultural products, swimming pools, lakes, water play areas, and water parks. Person-to-person transmission is unlikely because the oocysts must remain outside the human body for one to two weeks to become infectious.

Symptoms can begin between two days and more than two weeks after infection, typically appearing around one week after exposure. Common symptoms include watery diarrhea, loss of appetite, weight loss, abdominal cramps, bloating, increased gas, nausea, and fatigue. Less frequent symptoms may include vomiting, body aches, headache, and low-grade fever.

Dr. Rebecca Schein, an infectious disease specialist in the Health Sciences Division at Michigan State University, provided details on the symptoms. "Se trata sobre todo de diarrea muy líquida. Más de tres deposiciones al día, acompañadas de una sensación de hinchazón, plenitud y malestar," Schein said. Without treatment, symptoms can last from a few days to a month or more, though most individuals with a healthy immune system recover without intervention.

"Si se tiene un sistema inmunitario normal, la infección acabará desapareciendo, aunque el proceso puede llevar seis semanas," Schein said regarding recovery. Cyclosporiasis is typically treated with a combination of antibiotics. In individuals with weakened immune systems, symptoms may persist until treatment is received.

Detecting Cyclospora requires a specific test with special staining, as it is not included in standard multiplex stool tests. Dr. Max Teplitski, scientific director of the International Fresh Produce Association and former director of the Food Safety Division of the U.S. Department of Agriculture, commented on the parasite, saying, "La Cyclospora es un caso peculiar." Genetic comparison of the parasite is difficult because it reproduces sexually and exchanges DNA fragments, causing genetic variation between generations. PulseNet, a national network of laboratories, sequences the genes of bacteria that cause illness in people.

The Centers for Disease Control and Prevention recommends washing hands with soap and water before and after handling fresh fruits and vegetables to prevent cyclosporiasis. They also recommend washing fruits and vegetables thoroughly with running water before eating, cutting, or cooking them. Since the mid-1990s, raspberries have been associated with 12 Cyclospora outbreaks, basil with 11, salad mixes with 8, and cilantro with 6.