The identification of Cyclospora cayetanensis as a cause of infectious gastroenteritis
Testing Algorithm Delineates situation(s) when tests are added to the initial order. This includes reflex and additional tests.
For other diagnostic tests that may be of value in evaluating patients with diarrhea; the following algorithms are available in Special Instructions:
-Laboratory Testing for Infectious Causes of Diarrhea
-Parasitic Investigation of Stool Specimens Algorithm
Clinical Information Discusses physiology, pathophysiology, and general clinical aspects, as they relate to a laboratory test
Cyclospora cayetanensis is an apicomplexan protozoan parasite that causes watery diarrhea, anorexia, malaise, and weight loss. The extent of symptoms depends on the age and condition of the host and the infectious dose. The infection is usually self-limited, but symptoms can be severe and prolonged, particularly in immunocompromised patients. Cyclosporal diarrheal disease is endemic in many parts of the world, including Asia, India, Southeast Asia, and Latin America. Although most cases of cyclosporiasis have been seen in travelers to developing countries, outbreaks in the United States have been noted due to contaminated fruits and vegetables from Latin America. Transmission is via fecally contaminated food or water. If untreated, symptoms typically last for 10 to 12 weeks, and may follow a relapsing course. The infection usually responds to treatment with a sulfamethoxazole-trimethoprim drug combination.
Cyclospora cayetanensis oocysts are traditionally detected by modified acid-fast staining, in which the oocysts stain bright pink-red. However, the modified safranin stain has been shown to provide increased sensitivity over modified acid-fast method and produces a more rapid result. It is the method used in our laboratory to detect Cyclospora cayetanensis oocysts in fecal sediment.
See Laboratory Testing for Infectious Causes of Diarrhea and Parasitic Investigation of Stool Specimens Algorithm for other diagnostic tests that may be of value in evaluating patients with diarrhea.
Reference Values Describes reference intervals and additional information for interpretation of test results. May include intervals based on age and sex when appropriate. Intervals are Mayo-derived, unless otherwise designated. If an interpretive report is provided, the reference value field will state this.
If positive, reported as Cyclospora cayetanensis detected.
A report of Cyclospora cayetanensis detected indicates the presence of this parasite in the patient's feces.
Cautions Discusses conditions that may cause diagnostic confusion, including improper specimen collection and handling, inappropriate test selection, and interfering substances
The full spectrum of disease and the extent of carriage without disease have not been determined. In addition, the exact sensitivity and specificity of the stain have also not been determined.
Cryptosporidium oocysts do not reliably stain with the modified safranin stain. If Cryptosporidium is suspected, the specific enzyme-linked immunosorbent assay (CRYPS / Cryptosporidium Antigen, Feces) for this organism is recommended. Alternatively, the GIP / Gastrointestinal Pathogen Panel, PCR, Feces may be performed to detect this organism as well as other common infectious causes of diarrhea.
Clinical Reference Provides recommendations for further in-depth reading of a clinical nature
1. Chacin-Bonilla L: Epidemiology of Cyclospora cayetanensis: A review focusing in endemic areas. Acta Trop 2010;115(3):181-193
2. Ortega YR, Sanchez R: Update on Cyclospora cayetanensis, a food-borne and waterborne parasite. Clin Microbiol Rev 2010;23(1):218-234