Cyclospora

Coccidian Parasite in Eimeriidae family
Organism: Cyclospora cayetanensis
1. Infects the Small Intestine in humans
2. Humans are the only known hosts
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)
Worldwide distribution
1. Latin America
2. Egypt
3. Sub-Saharan Africa
4. India
5. Southeast Asia
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
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

Cyclospora PCR (preferred)
1. Test Sensitivity and Test Specificity approach 95%
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

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
Other agents (variably effective with high failure rates)
1. Ciprofloxacin 500 mg twice daily for 7 days
2. Nitazoxanide