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Epic Test Code LAB257 C. difficile -Nucleic Acid Amplification test (NAAT) with Reflex to Toxin

Important Note

For inpatient orders provider will need to reference CDIFF order set 739.

Performing Location(s)

BMC

Synonyms

Clostridium difficile
Clostridium difficile toxin

Specimen Type

Random Liquid  Stool

Preferred Container

Carey Blair Media (ETM, red top transport tube)

Alternate Container

Sterile Container

Stool sample must be placed in Carey Blair Media (ETM, Red top transport tube) within 2 hours of collection.

Volume Required

1 g or 5mL liquid Stool

Storage Requirements

Stool in ETM (Carey Blair) Ambient (22-25°C) 3 days
Fresh Fecal Specimen Refrigerated (2-8°C) 3 days
Fresh Fecal Specimen Frozen ≤-10° C 3 days

Transportation Needs

Transport to lab as soon as possible.

If immediate transport to the lab is not possible, specimen must be refrigerated

Causes for Rejection

Mislabeled or unlabeled specimen
Formed Stool
Swab - Rectal, Stool
Frozen specimen in ETM (Carey Blair)
Incorrect Transport Media (Formalin, Proto-fix, SAF,MIF or PVA)
> 72 hours refrigerated or Ambient
Non- stool samples
Stool sample not placed in Carey Blair Media (ETM, Red top transport tube) within 2 hours of collection.

 

Reference Values

Population

Test

Units

Reference Range

All Populations

C.diff NAAT

None

Negative

All Populations

C.diff Toxin

None

Negative

Reflex Testing

When C.diff NAAT is positive specimen will autimatically reflex to C.diff toxin LAB***(Lab Orderable only).  

Available STAT

No

Days of Analysis

All

Additional Information

Clostridioides (Clostridium) difficile NAAT: Detects but does not differentiate toxin A gene (tcdA) and toxin B gene (tcdB). The presence of C.diff toxin will be performed on all positive C.diff NAAT specimens.  A positive result may reflect asymptomatic carriage or C difficile-associated diarrhea.

The following criteria apply for submitting stools for patients suspected of having C.difficile diarrhea:

MORE THAN ONE SAMPLE IS NOT WARRANTED
SAMPLES WILL NOT BE ACCEPTED FOR REPEAT TESTING WITHIN 7 DAYS
SAMPLES ARE NOT TO BE SUBMITTED FOR “TEST OF CURE”.

In invalid results are obtained a 2nd sample will be requested.

 

 

 

Methodology

Nucleic Acid Amplification test (NAAT)

CPT Code

87493
 

Last Updated

14-Dec-23 BHD