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HelpTest Code CRYPS Cryptosporidium Antigen, Feces
Reporting Name
Cryptosporidium Ag, FUseful For
Establishing the diagnosis of intestinal cryptosporidiosis
Testing Algorithm
For other diagnostic tests that may be of value in evaluating patients with diarrhea; the following algorithms are available:
Performing Laboratory
Mayo Clinic Laboratories in Rochester
Specimen Type
FecalSpecimen Required
Submit only 1 of the following specimens:
Specimen Type: Preserved feces
Supplies:
-Formalin 10% Buffered Neutral 15 mL (T466)
-Stool Collection Kit, Random (T635)
Container/Tube:
Preferred: Stool container with 10% buffered formalin preservative
Acceptable: SAF (sodium acetate formalin)
Specimen Volume: 5 grams
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 grams
Specimen Stability Information: Frozen 60 days
Specimen Minimum Volume
1 gram
Specimen Stability Information
| Specimen Type | Temperature | Time | Special Container |
|---|---|---|---|
| Fecal | Varies | ||
Special Instructions
Reference Values
Negative
Day(s) Performed
Monday through Friday
Test Classification
This test has been cleared, approved, or is exempt by the US 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 |
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 Cryptosporidium 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 because 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 older adults, 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 this test, or the multiplex gastrointestinal polymerase chain reaction (PCR) panel (GIP / Gastrointestinal Pathogen Panel, PCR, Feces), is recommended for sensitive and specific detection. This 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.
For more information about diagnostic tests that may be of value in evaluating patients with diarrhea, see the following:
Interpretation
A positive enzyme-linked immunosorbent assay result indicates the presence of antigens of cryptosporidium and is interpreted as evidence of infection with that organism.
Interpretation of results should be correlated with patient symptoms and clinical picture.
Cautions
Examination of at least 2 fecal specimens may be required to detect Cryptosporidium using antigen testing.
Feces containing large amounts of white or red blood cells may produce false-positive results.
Clinical Reference
1. Centers for Disease Control and Prevention (CDC): Parasites-Cryptosporidium (also known as "Crypto"). CDC; Updated July 1, 2019. Accessed October 31, 2022. Available at www.cdc.gov/parasites/crypto/index.html
2. Garcia LS, Arrowood M, Kokoskin E, et al. Practical guidance for clinical microbiology laboratories: Laboratory diagnosis of parasites from the gastrointestinal tract. Clin Microbiol Rev. 2017;31(1):e00025-17. doi:10.1128/CMR.00025-17
Report Available
1 to 3 daysSpecimen Retention Time
Fresh/Frozen: 1 week; Preserved specimens: 1 weekReject Due To
| Grossly bloody (containing no visible feces) Very mucoid feces Specimen preserved in ECOFIX (green cap), C and S (orange cap), or methiolate formalin (MF) Duodenal aspirates Small bowel aspirates |
Reject |
Method Name
Enzyme-Linked Immunosorbent Assay (ELISA)
Forms
If not ordering electronically, complete, print, and send 1 of the following forms with the specimen:
-Gastroenterology and Hepatology Test Request (T728)
-Microbiology Test Request (T244)
Secondary ID
80335Supportive Data
The sensitivity, specificity, positive predictive value and negative predictive value of the enzyme-linked immunosorbent assay were 98%, 98%, 98%, and 98.5%, respectively, as determined by examination of 130 fecal specimens by conventional microscopy and by enzyme-linked immunosorbent assay.