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Test Code M221 Varicella-Zoster Virus (VZV) DNA Detection by PCR

Performing Laboratory

Barnes-Jewish Hospital Laboratory

Methodology

Polymerase Chain Reaction (PCR) performed on the Focus Integrated Cycler

Specimen Requirements

Acceptable Specimens:

Whole blood (lavender-top/EDTA tube), Swab in viral transport medium, or CSF
 

Collection Procedure:

Blood

For BJH Patients:  Call Laboratory Medicine resident at digital pager 314-747-1320 for approval before drawing the specimen.

1. Draw blood into lavender-top/EDTA tube. Avoid hemolysis.

2. Maintain sterility and forward promptly at ambient temperature only.

 

Swab

1. Obtain a vial of universal/viral transport medium (UTM) with collection swab

2. Collect specimen

3. Place the swab in labeled UTM vial, break off shaft of swab and discard excess piece of shaft. To prevent leaking, make sure the swabs do not interfere with tightening cap on vial.

 

Note:

1. Specimen source is required

 

CSF
1. Aseptically collect ≥1 mL of CSF.

2. Place in a leak-proof screw-capped, sterile container.

3. Maintain sterility and forward promptly.

4. If transport is delayed, refrigerate specimen.

For BJH Patients: Laboratory medicine resident review and approval is required for CSF specimen requests.

 

 

Day(s) Test Set Up

Monday through Sunday

Turnaround Time:
STAT: not available
Routine: 1- 3 days, Final report available the day of testing

Reference Values

Negative

Test Classification and CPT Coding

Test Classification:

This assay utilizes ASR’s (analyte specific reagents) and is not FDA cleared.  This test was developed and its performance has been evaluated by the Barnes Jewish Molecular Infectious Disease Laboratory for performance on whole blood, CSF and lesion swabs.

Assay Limit of Detection:

Whole Blood:  500 copies/mL

CSF: 500 copies/mL

Swabs:  5,000 copies/ml

Limitations:

-The detection of viral nucleic acid is dependent upon proper sample collection, transport, handling and storage. Failure to observe proper procedures in any one of these steps can lead to incorrect results.

-False-negative results may occur if the viruses are present at a level that is below the analytical sensitivity of the assay or if the virus has genomic mutations, insertions, deletions, or rearrangements or if performed very early in the course of illness.

-Most adults have been exposed to VZV at some point during their lifetime and can transiently have detectable virus from different sample types with or without symptomatology.  Positive results should be interpreted in the appropriate clinical context.

 

CPT Code:

87798

Additional Information

For BJH Laboratory Use Only

Minimum Volume:

Blood: 1 mL of EDTA
CSF: 0.5 mL

Laboratory Processing Instructions:
BJH Microbiology will forward to the performing laboratory.

Specimen Requirements Additional Information

Blood- Ambient/Refrigerate/Frozen OK

Swabs- Ambient/Refrigerate/Frozen OK

CSF- Ambient/Refrigerate/Frozen OK

 

Refrigerated specimens must be tested within 7 days
Frozen specimens must be tested within 30 days