Sign in →

Test ID: CRYPS Cryptosporidium Antigen, Feces

Reporting Name

Cryptosporidium Ag, F

Useful For

Establishing the diagnosis of intestinal cryptosporidiosis

Clinical Information

Cryptosporidia are small apicomplexan protozoan parasites that infect the intestinal tract of humans and animals. They were conventionally categorized as coccidia, but are now known to be more closely related to the gregarines. Many species may infect humans, with the most common being Cryptosporidium hominis and C parvum. Infected humans and animals shed small (4-6 micrometer in diameter) infectious oocysts in their stool, and these can subsequently contaminate and survive in recreational and drinking water supplies.

 

Infection of humans occurs by the fecal-oral route or via ingestion of contaminated water or food. Infection is easily acquired, with an infectious dose of approximately 100 oocysts. Waterborne transmission is a primary mode of transmission and is commonly responsible for human outbreaks. This is due to the fact that Cryptosporidium species oocysts are resistant to cold temperatures and chlorine, and require extensive filtration or water treatment to remove them from drinking water.

 

The incubation period is typically 7 to 10 days following exposure. While most patients have symptoms, approximately 30% of infected individuals are asymptomatic. When symptoms are present, they usually include profuse watery diarrhea, malaise, anorexia, nausea, crampy abdominal pain, and low grade fever. Infection is usually self-limited in immunocompetent individuals, with resolution of symptoms in 10 to 14 days. However, diarrhea can be prolonged and life-threatening in immunocompromised patients such as those with AIDS, infants, and the elderly, and result in severe dehydration and wasting.

 

The fecal ova and parasite examination is an insensitive method for detecting Cryptosporidium, given the small size of the oocysts and their lack of trichrome staining. Instead, use of the Cryptosporidium antigen test (CRYPS / Cryptosporidium Antigen, Feces) or the multiplex gastrointestinal PCR panel (GIP / Gastrointestinal Pathogen Panel, PCR, Feces) is recommended for sensitive and specific detection. The antigen test is ideal for situations in which cryptosporidiosis is highly suspected (eg outbreak scenarios), whereas the PCR panel allows for simultaneous detection of multiple parasitic, viral, and bacterial causes of diarrhea.

 

See Parasitic Investigation of Stool Specimens Algorithm and Laboratory Testing for Infectious Causes of Diarrhea in Special Instructions for more information about diagnostic tests that may be of value in evaluating patients with diarrhea.

Interpretation

A positive enzyme-linked immunosorbent assay (ELISA) indicates the presence of antigens of cryptosporidium and is interpreted as evidence of infection with that organism.

 

The sensitivity, specificity, and positive predictive value of the ELISA were 87%, 99%, and 98%, respectively, as determined by examination of 231 fecal specimens by conventional microscopy and by ELISA.

Testing Algorithm

For other diagnostic tests that may be of value in evaluating patients with diarrhea; the following algorithms are available in Special Instructions:

-Parasitic Investigation of Stool Specimens Algorithm

-Laboratory Testing for Infectious Causes of Diarrhea

Analytic Time

Same day/1 day

Day(s) and Time(s) Performed

Monday through Saturday; 1 p.m.

Clinical Reference

Centers for Disease Control and Prevention: Parasites-Cryptosporidium (also known as "Crypto"). Accessed 10/16/2019. Available at www.cdc.gov/parasites/crypto/index.html

Method Name

Enzyme-Linked Immunosorbent Assay (ELISA)

Specimen Type

Fecal


Specimen Required


Submit only 1 of the following specimens:

 

Specimen Type: Preserved feces

Supplies: Formalin 10% Buffered Neutral (T466); Stool Collection Kit, Random (T635)

Container/Tube:

Preferred: Stool container with 10% buffered formalin preservative

Acceptable: SAF (sodium acetate formalin)

Specimen Volume: 5 g

Specimen Stability Information: Ambient (preferred) 60 days

 

Specimen Type: Unpreserved feces

Supplies: Stool container, Small (Random), 4 oz (T288); Stool Collection Kit, Random (T635)

Container/Tube: Stool container

Specimen Volume: 5 g

Specimen Stability Information: Frozen 60 day


Specimen Minimum Volume

1 g

Specimen Stability Information

Specimen Type Temperature Time Special Container
Fecal Varies

Reference Values

Negative

Test Classification

This test has been cleared, approved or is exempt by the U.S. Food and Drug Administration and is used per manufacturer's instructions. Performance characteristics were verified by Mayo Clinic in a manner consistent with CLIA requirements.

CPT Code Information

87328

LOINC Code Information

Test ID Test Order Name Order LOINC Value
CRYPS Cryptosporidium Ag, F 6371-9

 

Result ID Test Result Name Result LOINC Value
24086 Cryptosporidium Ag, F 6371-9

Forms

If not ordering electronically, complete, print, and send 1 of the following forms with the specimen:

-Gastroenterology and Hepatology Client Test Request (T728)

-Microbiology Test Request (T244)

Mayo Clinic Laboratories | Neurology Catalog Additional Information:

mml-CNS-Infections, mml-Pediatric