AAFP | Cyclosporiasis: What Family Physicians Need to Know

Symptoms resemble many common gastrointestinal illnesses (e.g., viral gastroenteritis, food poisoning, medication side effect, C. diff infection). Any patient with prolonged or relapsing watery diarrhea should prompt consideration of Cyclospora, especially during summer produce-associated outbreak season, even if initial testing is negative.
Fresh produce remains a common source of exposure. Washing produce is a recommended food safety practice, but it cannot be relied upon to eliminate Cyclospora contamination.
Specifically request Cyclospora laboratory testing on stool specimens because routine stool culture and ova and parasite (O&P) examinations do not reliably detect the parasite. Molecular (PCR-based) diagnostic testing or Cyclospora smear are usually needed for detection.
Physicians should report cases to their local Health Department.

Treat confirmed cases of cyclosporiasis with trimethoprim-sulfamethoxazole (TMP-SMX) for immunocompetent adults; consider longer courses (3-4 weeks) or higher frequency dosing (3-4 times daily) for patients with immunocompromising conditions.
Standard adult dosing: TMP 160 mg/SMX 800 mg, orally twice daily, 7-10 days.
Though TMP-SMX is considered the treatment of choice for pediatric patients over age 2 months, it is not currently FDA-approved. Dosing is weight-based.
Treatment shortens course of symptoms, but Cyclospora infections can be self-resolving.

Additional Considerations: Illness may persist for weeks if untreated and symptoms may relapse.

Limited evidence suggests sulfa-allergic patients may use ciprofloxacin (500mg orally twice daily) or nitazoxanide (500mg orally twice daily, 3 days). If other options fail, pyrimethamine and folinic acid (used to treat cystoisosporiasis in sulfa-allergic patients) could be considered.