Test Code LAB4885 Herpes Simplex Virus (HSV) Detection by PCR
Performing Laboratory
Barnes-Jewish Hospital Molecular Infectious Disease Laboratory.
Methodology
Polymerase Chain Reaction (PCR) performed on the DiaSorin Liaison MDX.
Specimen Requirements
Acceptable Specimens:
Whole blood (Lavender-top/EDTA tube), Bronchoalveolar lavage, Bronchial wash, tracheal aspirate, Swab in viral transport medium, or CSF
Collection Procedure:
Blood
- Draw blood into Lavender-top/EDTA tube. Avoid hemolysis.
- Maintain sterility and forward promptly at ambient temperature only.
- Whole blood is required for testing. (Plasma or serum is not acceptable.)
Bronchial Alveolar Lavage (BAL), Bronchial Washes, or Tracheal Aspirate
- Aseptically collect at least 1.0 mL of BAL, bronchial wash specimen, or tracheal aspirate.
- Place specimen in a labeled, screw-capped, sterile container.
- Maintain sterility and forward promptly.
Swab
- Obtain a vial of universal/viral transport medium (UTM) with collection swab
- Collect specimen
- 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.
CSF
- Aseptically collect ≥1 mL of CSF.
- Place in a leak-proof screw-capped, sterile container.
- Maintain sterility and forward promptly.
- If transport is delayed, refrigerate specimen.
Note:
- Specimen source is required.
- 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
Test Classification and CPT Coding
Test Classification:
This assay is FDA cleared for performance on genital swabs and CSF, though has also been evaluated by the Barnes Jewish Molecular Infectious Disease Laboratory for performance on extra-genital swabs, lower respiratory samples, and whole blood.
Assay Limit of Detection:
Whole blood and lower respiratory specimens: 500 copies/mL for HSV-1 and HSV-2
Genital swab specimens: 160 TCID50 for HSV-1, 10 TCID50/mL for HSV-2
Extra-genital swab specimens: 1,000 copies/mL for HSV-1, 100 copies/mL for HSV-2
CSF: 40 TCID50 for HSV-1, 20 TCID50/mL for HSV-2
Interpretive:
HSV type routinely reported for positive CSF and whole blood specimens. Both HSV-1 and HSV-2 are potentially spread through sexual contact. Typing results for other specimen types are available upon request by contacting Barnes Jewish Hospital customer services (314-362-1470), though should not be used as the sole determination of acquisition route.
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.
- When very high levels of HSV-1 are present with very low levels of HSV-2, the signal from the HSV-2 reaction may not be adequate to be detected, due to competitive interference.
- Both HSV-1 and HSV-2 are potentially spread through sexual contact. Typing results should not be used as the sole determination of acquisition route.
- Most adults have been exposed to HSV 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:
87529
Reference Values
Negative
Specimen Transport Temperature
Blood-Ambient/Refrigerate/Frozen OK
Bronchial Alveolar Lavage (BAL), Bronchial Washes, or Tracheal Aspirate- 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
Additional Information
For BJH Laboratory Use Only
Minimum Volume:
Blood: 1 mL of EDTA
Bronchial Alveolar Lavage (BAL), Bronchial Washes, or Tracheal Aspirate: 0.5 mL
CSF: 0.5 mL
Laboratory Processing Instructions:
BJH Microbiology will forward to the performing laboratory.