Cyclosporiasis Outbreak 2026: 145 Cases Across 17 States, CDC Alert for Health Care Workers

As of mid-June 2026, the CDC is monitoring an expanding cyclosporiasis outbreak affecting 17 states, including Florida and Georgia, with 145 confirmed cases of this intestinal illness caused by the microscopic parasite Cyclospora cayetanensis. For infection prevention and control (IPC) health care workers, understanding this emerging threat is critical to protecting patients and containing transmission.

What IPC Professionals Should Know

Cyclosporiasis is a gastrointestinal disease that spreads through contaminated food or water, not person-to-person. The parasite causes diarrhea, cramps, nausea, and fatigue, with an incubation period of approximately 7 to 10 days after exposure. The 2026 outbreak has primarily affected individuals aged 5 to 86 (median age 42), with 61% of domestic cases occurring in females. While 20 hospitalizations have been documented, no deaths have been reported.

The illness is nationally notifiable in 47 states, Washington DC, and New York City, meaning health care providers are required to report confirmed cases to local health departments. This reporting requirement is essential for outbreak investigation and surveillance efforts.

Clinical Presentation and Diagnosis

Health care workers should maintain a high index of suspicion for cyclosporiasis in patients presenting with:

• Acute watery diarrhea (often profuse)
• Abdominal cramping and pain
• Nausea, vomiting, and loss of appetite
• Fatigue and malaise
• Fever (less common)
• Symptoms typically last for 2 weeks if untreated

Diagnosis requires stool microscopy to identify Cyclospora oocysts. Multiple stool samples may be necessary, as parasite shedding can be intermittent. Some laboratories use special staining techniques to enhance detection.

Treatment and Management

For patients with sulfa allergies, alternative antibiotic regimens should be considered in consultation with infectious disease specialists.

Supportive care is essential, including maintaining adequate hydration, monitoring electrolyte balance, and managing symptoms as needed. Most patients recover fully with appropriate treatment, though immunocompromised individuals may experience prolonged illness.

Current Outbreak Status

All 145 domestic cases acquired between May 1 and June 6, 2026, involved no international travel in the preceding 2 weeks, indicating a domestic food or water source. The CDC and FDA are actively investigating multiple multistate clusters, though no confirmed food source has been identified yet. An additional 45 travel-related cases were reported among individuals who became ill after consuming contaminated food or water outside the US.

Resources and Reporting

CDC Cyclosporiasis Information:
https://www.cdc.gov/parasites/cyclosporiasis/index.html

World Health Organization Resources on Foodborne Parasitic Infections:
https://www.who.int/news-room/fact-sheets/detail/foodborne-trematode-infections

For Ohio Health Care Workers:
Contact the Ohio Department of Health at 1-888-246-5005 or visit odh.ohio.gov for state-specific surveillance data and reporting requirements.

Infection Prevention Recommendations

While person-to-person transmission is rare, standard precautions should be maintained for hospitalized patients with acute diarrhea. Emphasize hand hygiene, especially after patient contact and before food handling. Educate patients about food and water safety to prevent secondary spread.

IPC professionals should collaborate with epidemiology and infectious disease teams to identify potential sources of exposure and support outbreak investigations. Early recognition and reporting of cyclosporiasis cases remain critical tools in controlling this emerging seasonal threat.