The McHenry County Department of Health announced on Friday that it is actively investigating a sharp increase in cyclosporiasis cases within the county. Since June 25, officials have identified 61 confirmed infections, a figure that exceeds the number reported during the same timeframe in 2025 by more than five times. The department emphasized that the investigation is ongoing and that case counts may continue to change as new information emerges.
Understanding Cyclosporiasis and Its Impact
Cyclosporiasis is a gastrointestinal illness caused by the parasite Cyclospora cayetanensis. Symptoms typically appear about a week after exposure and can include watery diarrhea, loss of appetite, weight loss, stomach cramps or bloating, nausea, fatigue, and a low‑grade fever. Without treatment, these symptoms may persist for several weeks or longer, often improving temporarily before recurring. Prolonged diarrhea raises the risk of dehydration, and individuals who notice reduced urination, dizziness, or headaches should seek medical attention promptly.
Health officials advise anyone experiencing diarrhea that lasts more than a couple of days to contact a primary‑care provider or seek medical evaluation, testing, and appropriate treatment. While the exact source of the current outbreak has not been identified, cyclosporiasis is historically linked to the consumption of contaminated fresh produce or water. Past outbreaks have been associated with a range of items, including leafy greens such as lettuce, fresh herbs, snow peas, green onions, and various berries.
Prevention Recommendations for Residents
In the absence of a confirmed food source, the department urges residents to adhere to routine food safety practices to lower the risk of infection. Recommended steps include rinsing all fresh fruits and vegetables under running water and gently scrubbing or wiping produce before cutting or cooking. Firm items like melons and cucumbers should be scrubbed with a clean produce brush. Additionally, washing and sanitizing cutting boards, utensils, containers, and other surfaces that come into contact with fresh produce is essential.
Hand hygiene remains a cornerstone of prevention; anyone preparing food, handling fresh produce, or using the restroom should wash hands thoroughly with soap and water. While thorough washing reduces risk, officials note that cooking produce to an internal temperature of 158 °F (70 °C) is more effective because it inactivates the Cyclospora parasite.
“With no specific food source identified, consumers can reduce, but not completely eliminate, their risk by carefully washing, preparing, and storing fresh produce,” the health department said in its statement. The department will continue monitoring the situation and promises to provide updates as more information becomes available.
Looking Ahead
The surge in cyclosporiasis cases underscores the importance of vigilant food safety practices, especially during periods of heightened outbreak activity. As the investigation proceeds, public health officials remain focused on identifying any common exposure points that could explain the rapid increase. Residents are encouraged to stay informed through official health department communications and to seek medical care promptly if they develop concerning symptoms.
Mitchell Landsberg is the senior reporter for News Raise and focuses on Technology. Mitchell regularly writes about social media platforms and how influencers, industry and general people use them to communicate and make money.
