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Cyclospora Infection (Cyclosporiasis)

What Is Cyclospora Infection (Cyclosporiasis)?

  • The Cyclospora parasite causes cyclosporiasis when humans ingest contaminated water or food containing Cyclospora sporulated oocysts.
  • Symptoms and signs of Cyclospora infections include watery diarrhea, gas, cramping, bloating, nausea, weight loss, appetite loss, and fatigue.
  • Medical care should be sought if symptoms last a week or more, if a person has traveled through an endemic area, or if they become dehydrated and weak.
  • Diagnosis of Cyclospora infections require special laboratories and lab tests to detect the parasites.
  • The only CDC-recommended treatment is the antibiotic trimethoprim-sulfamethoxazole (Bactrim, Septra, Sulfatrim).
  • Self-care at home consists of symptomatic treatment and completing oral antibiotic therapy.
  • Follow-up is not usually required if treatment is effective, but follow-up for certain individuals is recommended.
  • The prognoses of most treated Cyclospora infections is good to excellent; the prognoses of untreated infections range from good to a few poor outcomes.
  • Complications of Cyclospora infections may include a relapsing illness, malabsorption, cholecystitis, Reiter's syndrome (reactive arthritis), dehydration, and electrolyte problems in some patients.
  • There is no vaccine to prevent Cyclospora infections; the CDC recommends avoiding water and foods contaminated with human feces and adherence to FDA guidelines for food growers and food packagers.

What Are the Causes and Risk Factors for Cyclospora Infection?

Cyclospora infection (cyclosporiasis) is caused by a parasite that infects human small intestinal tract cells. The parasite is named Cyclospora cayetanensis; it's a single-cell parasite that can only be viewed with a microscope. The parasite was recently discovered in 1977 and only named in 1994. The parasite has a complicated life cycle that requires development in human intestinal cells. Sporulated oocysts are the infective stage of the parasite. Sporozoites infect small intestinal cells after oocysts spore breaks open, a process termed excystation, which is followed by several developmental steps). After development, non-sporulated oocysts passed out of the body in feces must mature (sporulate) in the environment before they can infect another human.

Anyone at any age is at risk of getting cyclosporiasis if they ingest water or foods contaminated with sporulated oocysts. Most individuals infected live in tropical or subtropical regions. Most of the U.S. outbreaks have been relatively small and linked to imported fresh produce (raspberries, snow peas, basil, and lettuce) but not to frozen or canned produce. A large outbreak in 2013 was linked to imported salad mix and cilantro. This large outbreak involved 25 states, primarily Iowa, Nebraska, and Texas.

Medically Reviewed by a Doctor on 12/9/2016

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