Clinical Guidance
Consider Cyclosporiasis in your differential for patients with gastrointestinal illness during this outbreak. Below: presentation, testing, treatment, and reporting.
Clinical presentation
Cyclosporiasis is an intestinal illness of variable severity caused by Cyclospora cayetanensis. The most common symptom is watery diarrhea, which may be profuse and relapsing. Infection is usually self-limiting, but untreated patients may have remitting, relapsing symptoms for weeks to months.
Per ODH, common symptoms include watery diarrhea (most common), loss of appetite, weight loss, abdominal cramping and bloating, flatulence, nausea, and fatigue. Less common symptoms include vomiting, body aches, and low-grade fever. The typical incubation period is about 7 days (range roughly 2 days to 2 weeks).
Diagnostic testing
Testing for Cyclospora is not routinely performed in most U.S. laboratories, and not all GI panels include a target for it - so it must be specifically requested when indicated. The following tests can be used:
| Method | Notes |
|---|---|
| O&P | Ova and parasite exam - e.g., microscopy and stained smears. Oocysts are autofluorescent and variably acid-fast after modified acid-fast staining. |
| GI PCR panel | Multiplex gastrointestinal panel that includes a Cyclospora target (e.g., BioFire FilmArray®). Confirm the panel in use includes the target. |
| Standalone PCR | A dedicated Cyclospora PCR test, not part of a panel. |
Collect multiple specimens
Oocyst shedding can be intermittent and at low concentrations. Submitting three stool specimens collected at least 48 hours apart within a 10-day period (e.g., Monday, Wednesday, Friday) is recommended; an estimated 90%+ of infections are detected when three stools are examined. Specimens sent to ODH Laboratory for Cyclospora testing cannot be preserved in formalin.
Treatment
Most immunocompetent patients recover without treatment. When indicated, cyclosporiasis is treated with a 7-to-10-day course of oral trimethoprim-sulfamethoxazole (TMP/SMX). Supportive care with rest and fluids is important for patients with diarrhea. Patients with HIV infection may require higher dosing and a longer course.
7–10 day oral course when treatment is indicated. Consider higher dose and longer duration for immunocompromised patients per CDC clinical guidance.
Reporting requirements
In Ohio, cyclosporiasis is a Class B reportable disease. Report a case, suspected case, and/or positive laboratory result to the local public health department where the patient resides by the close of the next business day. Reports and lab findings should be submitted through the Ohio Disease Reporting System (ODRS).
Key fields to capture include sensitive occupation or day care attendance, household illness, and travel history. Providers without ODRS access may use the Ohio Confidential Reportable Disease Form (HEA 3334).
Exclusion note
Per Ohio Administrative Code, a person with cyclosporiasis who works in a sensitive occupation (e.g., food handling, direct patient care, child care) or attends a child care center should be excluded and may return after diarrhea has ceased and effective antimicrobial therapy has begun.
Key takeaways
- There is a national outbreak of Cyclosporiasis, a parasitic GI illness commonly spread through contaminated food or water.
- There is currently no known cause for this specific outbreak.
- CCBH continues to investigate local cases and coordinate with state and federal partners.
- Include Cyclosporiasis in the differential and test for it specifically when managing patients with gastrointestinal illness.
Sources: Cuyahoga County Board of Health provider update (July 13, 2026); Ohio Department of Health, Infectious Disease Control Manual (Section 3: Cyclosporiasis, rev. 1/2026); U.S. CDC. This guidance supports, and does not replace, clinical judgment.
Reporting a case or need testing support?
Contact the CCBH Disease Team. Report suspected and confirmed cases through ODRS by the close of the next business day.