Cyclospora Infection (Cyclosporiasis) Clinical Presentation

Updated: Jul 16, 2021
  • Author: Chinelo N Animalu, MD, MPH, FIDSA; Chief Editor: Pranatharthi Haran Chandrasekar, MBBS, MD  more...
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After exposure in nonimmune individuals, the incubation period is usually1-14+ days (mean, 7 d). The onset of illness may be abrupt in as many as 30% of cases, with watery diarrhea containing mucus or blood. [17] It may be preceded by a flulike illness. [25] After a few days, acute symptoms subside and then may recur (61% of cases) in a waxing-waning pattern. Alternatively, a patient may experience persistent symptoms. The illness usually lasts 6-7 weeks but has been reported to persist for several months. The duration can be several months to a year in patients with HIV.

  • Watery diarrhea (may be explosive) with a median of 6 stools per day; frequency of diarrhea possibly many times higher; no diarrhea in some patients.

  • Anorexia

  • Weight loss (0.9-3.6 kg in one study)

  • Fatigue, often pronounced

  • Abdominal cramping

  • Belching

  • Abdominal bloating

  • Vomiting

  • Low-grade fever (25%)

  • Flatulence

  • Headache

  • Nausea



Vital signs are normal in most cases. Fever is unusual but, when present, is low grade. In the presence of moderate to severe dehydration, compensatory tachycardia, systolic blood pressure (SBP) less than 90 mm Hg, and decreased skin turgor may occur, and the patient may appear ill.



Risk for infection is secondary to the consumption of contaminated fruits, vegetables, water, or other foodstuffs (see Deterrence/Prevention for strategies that decrease the risk of acquiring this infection). The infectious inoculum is unknown, but is thought to be small (eg, ingestion of 10-100 oocysts). [26]