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Epic Test Code LAB1266 Rotavirus Antigen, Feces

Additional Codes

MML Code: ROTA

LIS Code: ROT

Reporting Name

Rotavirus Ag, F

Useful For

Investigation of patients with diarrhea, particularly infants, the elderly, and immunocompromised patients

 

Investigation of nosocomial diarrhea

Testing Algorithm

For information on other diagnostic tests that may be useful in the evaluation of a patient with diarrhea, see Laboratory Testing for Infectious Causes of Diarrhea.

Performing Laboratory

Mayo Clinic Laboratories in Rochester

Specimen Type

Fecal


Specimen Required


Specimen Type: Fresh unpreserved feces

Supplies: Stool Collection Kit, Random (T635)

Container/Tube:

Preferred: Sterile fecal container

Acceptable: Swab

Specimen Volume: 5 to 10 grams

Collection Instructions: Place specimen in a tightly sealed plastic bag.


Specimen Minimum Volume

1 gram

Specimen Stability Information

Specimen Type Temperature Time Special Container
Fecal Frozen (preferred) 7 days
  Refrigerated  72 hours

Reference Values

Negative

Day(s) Performed

Monday through Friday

CPT Code Information

87425

Clinical Information

Rotavirus is a major cause of nonbacterial gastroenteritis, especially in infants and very young children (6 months-2 years of age) who have not received the rotavirus vaccine. Infection may be entirely asymptomatic or produce a spectrum of disease ranging from mild gastroenteritis to severe diarrhea and vomiting with dehydration. Infection usually begins acutely and lasts for 4 to 8 days. In temperate climates, rotaviral infections are seasonal; they peak in frequency during the winter months and are uncommon during the summer. Rotaviral gastroenteritis is, therefore, sometimes called "winter vomiting disease."

 

Infection is more likely to be symptomatic in preterm infants, immunosuppressed patients, and elderly individuals, especially those living in nursing homes or other confined quarters. In other children and adults, rotavirus infections are usually subclinical and may be associated with asymptomatic shedding of rotavirus in the feces.

 

Rapid and accurate detection of rotavirus antigens in fecal specimens may lead to better patient management, particularly in hospitalized or institutionalized patients.

Interpretation

Peak viral counts are reported to occur on days 3 to 5 after onset of symptoms. The virus is eliminated from the infected individual within a few days following acute infection. Specimens collected 8 days or more after onset of symptoms may not contain enough rotavirus antigen to produce a positive reaction.

 

A prolonged carrier state has been recognized with rotavirus infection.

 

The rate of positive test results may vary due to age, weather, seasonal factors, geographic location, and the general health environment for the group under study.

 

Information on other diagnostic tests that may be of value in evaluating patients with diarrhea can be found in Laboratory Testing for Infectious Causes of Diarrhea.

Cautions

Fecal specimens should be collected as soon after onset of symptoms as possible.

 

Do not collect specimens in containers having media, preservatives, animal serum, or detergent as any of these may interfere with the assay.

 

A positive result does not preclude the presence of other pathogenic organisms. While the relationship between rotavirus and gastroenteritis is well established, coinfection with bacterial or parasitic pathogens is possible. If suspected, testing for other enteric pathogens should be performed in parallel with the rotavirus antigen test.

 

Results of the rotavirus antigen assay must be interpreted with caution. A negative result does not exclude the possibility of rotavirus infection, as too small a quantity of virus or inadequate or improper sampling may cause a false-negative result.

Supportive Data

This enzyme immunoassay antigen detection method has 100% sensitivity and 92% specificity when compared to transmission electron microscopy (EM), the method initially used to detect virus in fecal and intestinal biopsy specimens and the standard to which rotavirus diagnostic tests are compared. When compared to EM and RNA analysis, in combination, the specificity increases to 97%.

Report Available

1 to 3 days

Specimen Retention Time

7 days

Reject Due To

Grossly bloody (containing no visible feces)
Very mucoid feces
Feces received in any preservative (example: Ecofix, formalin, PVA, C and S media)
Reject

NY State Approved

Yes

Method Name

Enzyme Immunoassay (EIA)

Forms

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

-Microbiology Test Request (T244)

-Gastroenterology and Hepatology Test Request (T728)