Tracking the Cyclospora cayetanensis Outbreak in the United States

A rise in foodborne illnesses in the United States linked to Cyclospora (Cyclospora cayetanensis) began in May 2026 in New York. Since then, state health departments in Michigan, New York, Ohio, Illinois, North Carolina, and Texas, among others, have reported several thousand suspected and confirmed cases. As of July 9, 2026, the CDC confirms 843 domestically acquired cases across 31 states, with more than 1,500 additional cases under review and 86 hospitalizations. Midwest states are currently most impacted, including Ohio and Michigan, the latter of which is reporting numbers as high as 1,562 cases since June 22. 

Cyclospora is a microscopic parasite that causes cyclosporiasis, a gastrointestinal illness characterized by watery diarrhea, abdominal cramps, nausea, fatigue, loss of appetite, and, in some cases, prolonged or relapsing symptoms. Direct person-to-person transmission is uncommon. Investigators have not yet determined the contaminated food source, yet historically the parasite has been linked to consumption of fresh produce such as basil, cilantro, green onions, raspberries, snow peas, bagged salad mixes and leafy greens.  

With the current outbreak, officials state that there is no evidence of a single nationwide outbreak source and that it is most likely multiple clusters occurring simultaneously. Investigations are focused on identifying common food exposures among patients. Additional cases are expected as symptoms can take several days to a couple of weeks to appear after exposure.

Diagnostic testing is an important tool for health care practitioners and municipalities to identify, diagnose and track current and potential viral, bacterial and parasitic outbreaks like Cyclospora. bioMérieux helps both clinical care workers and municipalities to coordinate community responses, track trends overtime, and provide the right diagnosis and care to impacted individuals. 

WATCHFIRE^™ includes two separate panels, the WATCHFIRE^™ Respiratory Panel and the WATCHFIRE^™ Gastrointestinal Panel, which tests for Cyclospora cayetanensis, along with other common infections including E. coli, Salmonella, and Norovirus. Once these panels are run on the benchtop BIOFIRE^® FILMARRAY^® TORCH, data is aggregated on the cloud-based FIREWORKS^™ platform for analysis and monitoring.

“Timely pathogen identification is crucial, making it important for labs and clinical teams to have the right test, at the right time, wherever the patient is,” states John Osiecki, Vice President, Medical Affairs, bioMérieux. “Because these diagnostic panels test for 22 of the most common gastrointestinal pathogens from a single sample in about an hour, they can help guide treatment decisions, support public health surveillance, and inform an appropriate response. While there are several FDA-cleared multiplex panels that are commercially available for clinical diagnostic testing, not all of them include Cyclospora as a target.”

bioMérieux's 22-plex BIOFIRE® FILMARRAY® Gastrointestinal (GI) Panel and 11-plex BIOFIRE® FILMARRAY® Gastrointestinal (GI) Panel Mid are built on proven syndromic molecular technology that deliver results in about one hour. Each panel covers a broad range of bacterial, viral, and parasitic targets, including Cyclospora cayetanensis, E. coli, norovirus, Salmonella, and Campylobacter. With these multiplex assays, labs and clinical teams may not only optimize antimicrobial and other treatment decisions but also offer that care across outpatient and hospital-based settings. Unlike many causes of acute gastroenteritis, targeted antimicrobial therapy is recommended for cyclospora and can significantly shorten the duration of illness.

Accurate, timely results are critical in securing the correct diagnosis for a patient or determining appropriate next steps for public utilities. Anonymously aggregating these results into national and regional trends data provide actionable insights to health care practitioners and municipalities that wish to identify emerging trends and better prepare to respond. That’s what FIREWORKS does.

FIREWORKS is a centralized platform for real-time insights into system performance and pathogen trends, and it is viable with BIOFIRE® TORCH Systems including both wastewater surveillance WATCHFIRE® and the clinical BIOFIRE® FILMARRAY® Gastrointestinal Panels. Its Trends dashboard collects current and historical test results from participating BIOFIRE® FILMARRAY® and BIOFIRE® SPOTFIRE® systems. This data helps community health officials and healthcare teams to identify emerging trends and evaluate potential public health risks. 

“With the current outbreak of cyclospora, we have witnessed a jump this spring from a ‘normal’ 1-2% nation-wide positivity rate for Cyclospora on clinical gastrointestinal panels to a current trend of 10-12%,” states Jay Jones, Vice President, Data Science, bioMérieux. “We share these trends publicly on the FIREWORKS website to support community preparedness, outbreak awareness, and informed resource planning.”

As CDC and public health partners continue their investigations, timely laboratory confirmation remains an important element in understanding the epidemiology, geographic distribution, and potential sources associated with Cyclosporiasis cases.