Nearly 1,000 individuals in Michigan have been diagnosed with a parasitic infection that causes prolonged watery diarrhea. This outbreak is the largest in the state’s history and among the largest in the nation in recent years. No deaths have been reported, and the source of these cyclospora infections is still unidentified. Investigations are ongoing in 28 other states, including Ohio, where people near the Michigan border are also affected.
Current Situation in Michigan
Michigan officials first announced the outbreak when more than 170 cases had been identified since June 22, all in the southeastern region of the state. Typically, Michigan records about 50 cyclospora cases annually. By Wednesday, officials reported 992 cases, with approximately 40 resulting in hospitalization. Across the state line, Lucas County in Ohio reported 306 cases, contributing to over 400 cases in northwestern Ohio.
Dr. Natasha Bagdasarian, Michigan’s chief medical executive, acknowledged the challenge in investigating cyclospora surges, as pinpointing a food poisoning source can be difficult. However, there is a clear linked outbreak ongoing.
Understanding Cyclospora
Cyclospora is a microscopic, spherical parasite that often causes watery diarrhea with frequent and sometimes explosive bowel movements.
According to the U.S. Centers for Disease Control and Prevention, the illness, called cyclosporiasis, is not usually life-threatening and is generally treated with antibiotics. Outbreaks often occur in late spring and summer.
The parasite thrives in warm conditions, spreads through feces, and has historically infected individuals via fruits or vegetables exposed to contaminated irrigation water. While less common than other foodborne illnesses, such as salmonella and E. coli, cyclospora outbreaks in the U.S. have increased over the past decade, peaking in 2018 and 2019. Climate change and improved detection methods are believed to contribute to these increases.
Comparing Past Outbreaks
The lack of comprehensive data on cyclospora outbreaks poses challenges in determining exact case numbers. However, documented outbreaks with over 1,000 cases in the last 20 years are rare. Notable instances include a 1997 outbreak linked to Guatemalan raspberries and a 2019 outbreak associated with Mexican basil.
Melanie Firestone, a foodborne illness researcher, highlights several reasons for underreporting. Tests that detect other types of food poisoning might not catch cyclospora. Additionally, laboratory technicians cannot culture the parasite, complicating efforts to trace contaminated produce. Identifying common foods among those affected is often difficult due to shared ingredients used in various recipes.
Protective Measures Against Cyclospora
Individuals experiencing persistent diarrhea should consult healthcare providers to discuss cyclospora. The best preventive measure is avoiding potentially contaminated food or water. Thoroughly washing fresh produce is essential, though cyclospora can be tough to eliminate completely. Officials suggest purchasing whole heads of lettuce instead of prewashed and bagged varieties, removing the outer leaves, and washing under running water. Cooking vegetables when possible is also advisable.
As Michigan probes the outbreak’s source, enhanced detection and reporting efforts may explain the state’s prominent case numbers compared to other regions. While thousands of cyclospora cases are reported annually across the U.S., Michigan’s swift response is significant in managing the outbreak.