Lab Test

Antigen, Cryptosporidium

Cryptosporidium Antigen, Diarrhea

Test Codes





At least 2 weeks should elapse following barium administration before collection of specimen.

Specimen Collection Criteria

Collect: Random stool specimens in SAF, EcoFix or 10% Formalin (for routine Ova and Parasite examination), Cary-Blair or Para-Pak transport medium.

Also acceptable: Random stool specimen in a sterile collection container with no preservative.

Physician Office/Draw Specimen Preparation

Maintain preserved specimens at room temperature (20-26°C or 68-78.8°F) or refrigerated (2-8°C or 36-46°F) prior to transport. Unpreserved specimens must be refrigerated immediately after collection.

Preparation for Courier Transport

Transport: Stool specimen in SAF, EcoFix Cary-Blair or Para-Pak transport medium, at room temperature (20-26°C or 68-78.8°F), or unpreserved specimens, refrigerated (2-8°C or 36-46°F).

Rejection Criteria

  • More than one specimen per patient collected within a 24-hour period. 
  • Stool collected following a soap suds enema. 
  • Frozen specimens. 
  • Stool specimens that have been concentrated or treated with PVA, Protofix, or MIF fixatives. 
  • Specimens in Para-Pak or Cary-Blair transport cannot be older than 1 week from the date of collection. 
  • Fresh, unpreserved stool specimens not refrigerated and older than 2 hours.
  • All specimens older than 48 hours from time of collection. These samples are unacceptable for routine Ova and Parasite examination


Specimen Stability for Testing:

Room Temperature (20-26°C or 68-78.8°F): 2 hours (Unpreserved)
Room Temperature (20-25°C or 68-77°F): 7 days (Preserved)
Refrigerated (2-8°C or 36-46°F): 7 days
Frozen (-20°C/-4°F or below): Unacceptable

Specimen Storage in Department Prior to Disposal:

Refrigerated (2-8°C or 36-46°F): 7 days


Dearborn Microbiology Laboratory
Taylor, Trenton and Wayne sent to Dearborn Microbiology Laboratory.

Royal Oak Microbiology Laboratory
Farmington Hills, Grosse Pointe and Troy sent to Royal Oak Microbiology Laboratory for testing.


Saturday – Sunday, 24 hours a day.
Results available within 24 hours.

Reference Range

Negative for Cryptosporidium Antigen.

Test Methodology

Immunochromatographic Assay.


A single diagnostic assay should not be used as the only basis for forming a clinical diagnosis. Results should be correlated with patient symptoms and the overall clinical picture.

Clinical Utility

This assay aids in the diagnosis of cryptosporidiosis.

Clinical Disease

Cryptosporidiosis is caused by Cryptosporidium spp., a coccidian protozoan. Cryptosporidiosis is a parasitic infection of medical and veterinary importance. The parasite infects the epithelial cells of the GI, biliary and respiratory tracts of man as well as other vertebrates, including poultry and other birds, fish, reptiles, small mammals (rodents, cats, dogs) and large mammals (particularly cattle and sheep). The major symptom in human patients is diarrhea, that may be profuse and watery, preceded by anorexia and vomiting in children. The diarrhea is associated with cramping abdominal pain. General malaise, fever, anorexia, nausea, and vomiting occur less often. Infection may be asymptomatic. Symptoms usually wax and wane, but remit in 15 to 30 days in most immunologically healthy persons. Immunodeficient persons, especially persons with AIDS, may be unable to clear the parasite and the disease has a prolonged and fulminant clinical course (losing 3-6 liters of fluid/day), contributing to death. Symptoms of cholecystitis may occur in biliary tract infections; the relationship between respiratory tract infections and clinical symptoms is unclear.


Cryptosporidium oocysts have been identified in human fecal specimens from more than 50 countries on six continents. In developed areas such as the United States and Europe, the prevalence of infection ranges from less than 1% to 4.5% of individuals tested. In developing regions, the prevalence is significantly higher, ranging from 3% to 20%. Children over 2 years of age, animal handlers, travelers, homosexual men, and close personal contacts of infected individuals (families, health care and day-care workers) are at increased risk of infection (1).

Incubation Period

Not precisely known; 1 to 12 days is the likely range, with an average of about 7 days (1).


Fecal-oral, with person-to-person, animal-to-person, and waterborne transmission are all important. Oocysts, the infectious stage, appear in the stool at the onset of symptoms and continue to be excreted in the stool for several weeks after symptoms resolve; outside the body, they may remain infective for 2-6 months in a moist environment (1).


  1. Chin,J. (editor) Control of Communicable Diseases Manual, American Public Health Association, Washington, DC, 2021, 20th ed.
  2. Xiao, L., and Cama, V. 2011. Cryptosporidium. In: Versalovic, J., eds., Manual of Clinical Microbiology, 10th Edition. American Society for Microbiology Press, Washington, D.C.
  3. Garcia, L.S. 2010. Cryptosporidium parvuum. In: Garcia, L.S. (ed.) Diagnostic Medical Parasitology. ASM Press. Washington, D.C. 3rd edition.

CPT Codes

LOINC:  6371-9


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