Cyclospora

Aka: Cyclospora, Cyclosporiasis, Cyclospora cayetanensis

advertisement

II. Pathophysiology

  1. Coccidian Parasite in Eimeriidae family
  2. Organism: Cyclospora cayetanensis
    1. Infects the Small Intestine in humans
    2. Humans are the only known hosts
  3. Transmission via Cyclospora oocyst ingestion
    1. Waterborne Illness
      1. Endemic to some tropical and subtropical regions
    2. Foodborne Illness
      1. Fresh produce (outbreaks in U.S. and Canada)
      2. Infective dose is thought to be low (<100 oocysts)
    3. Fecal-oral transmission is unlikely
      1. Oocysts sporulate (over days to weeks) outside a host before they are once again infective
      2. Sporulation requires external Temperatures 72 to 90 F (22 to 32 C)
  4. Worldwide distribution
    1. Latin America
    2. Egypt
    3. Sub-Saharan Africa
    4. India
    5. Southeast Asia
  5. U.S. cases
    1. International travelers
    2. Ingesting contaminated fresh imported produce from endemic areas
      1. U.S. Outbreaks (e.g. contaminated salad greens) have occurred in spring, summer
  6. Course
    1. Incubation: 2-14 days (1 week on average)
    2. Variable course of a few days to months of illness
    3. More severe course (e.g. protracted Diarrhea) in Immunocompromised, or extremes of age

III. Symptoms

  1. Anorexia or weight loss (waxing and waning)
  2. Fatigue
  3. Low-grade fever may be present
  4. Nausea (and in some cases Vomiting)
  5. Non-bloody Diarrhea (may be explosive, may be bloody in some cases)
  6. Abdominal cramping and bloating
  7. Excessive Flatus

IV. Labs

  1. Cyclospora PCR (preferred)
    1. Test Sensitivity and Test Specificity approach 95%
  2. Ova and Parasite (microscopy)
    1. Variable detection rates are typically low
    2. Detection requires 3 or more samples collected every 2 to 3 days
    3. Modified acid fast stain or UV microscopy may improve Test Sensitivity

V. Management

  1. Trimethoprim-Sulfamethoxazole DS (Septra, Bactrim)
    1. Immunocompetent
      1. Dose: 1 DS tab twice daily for 7 to 10 days
    2. Immunodeficiency or HIV
      1. Initial: 1 DS tab four times daily for 3 to 4 weeks
      2. Suppression may be needed with 1 DS tab three times weekly
  2. Other agents (variably effective with high failure rates)
    1. Ciprofloxacin 500 mg twice daily for 7 days
    2. Nitazoxanide

VI. Complications

  1. Malabsorption
  2. Acalculous Cholecystitis (HIV patients)
  3. Guillain-Barre Syndrome
  4. Reactive Arthritis (Reiter's Syndrome)
    1. Inflammatory Oligoarthritis
    2. Eye inflammation (Iritis, Episcleritis, Conjunctivitis)
    3. Urethritis

VII. Course

  1. Without treatment, may persist for months or follow a relapsing course

VIII. Resources

  1. CDC Cyclosporiasis
    1. http://www.cdc.gov/parasites/cyclosporiasis/

IX. References

  1. (2015) Sanford Guide to antimicrobials, accessed IOS app 5/11/2016
  2. Ortega (2010) Clin Microbiol Rev 23(1): 218-34 +PMID:20065331 [PubMed]
  3. Pyzocha (2023) Am Fam Physician 108(5): 487-93 [PubMed]

Images: Related links to external sites (from Bing)

These images are a random sampling from a Bing search on the term "Cyclospora." Click on the image (or right click) to open the source website in a new browser window. Search Bing for all related images

Related Studies

Related Topics in Infectious Disease

advertisement