Varicella-Zoster Virus and Herpes Simplex Virus DFA with Reflex to Varicella-Zoster Virus Culture and Herpes Simplex Virus Culture
Also known as: VZV HSVFAC
Use
This test provides a rapid diagnostic approach for distinguishing between varicella-zoster virus (VZV) and herpes simplex virus (HSV) infections, which present with clinically similar lesions. Timely differentiation is crucial for appropriate patient management and treatment decisions. By employing direct fluorescent antibody (DFA) testing initially, with the option to reflex to culture if results are negative or inadequate, this test ensures reliable identification of the viral cause of the skin lesions.
Special Instructions
The test is New York state approved. If DFA results are negative or inadequate, cultures for VZV and HSV will be added, incurring additional charges. Proper specimen collection involves obtaining vesicle fluid, swabs, tissue, or skin scrapings during the first three days of a rash, and immediate transfer to viral transport media.
Limitations
The sensitivity of the DFA methodology is highly dependent on the adequacy of the specimen. If the specimen contains fewer than 20 cells, the DFA results will be categorized as 'inadequate.' Bone marrow, CSF, or whole blood are unsuitable for this testing, and certain swabs like calcium alginate, eSwab, dry or wood swabs are not acceptable. Immediate refrigeration is crucial since ambient and frozen conditions are unsuitable.
New York Approved
Methodology
Immunoassay (Immunofluorescent Stain)
Biomarkers
LOINC Codes
- 5882-6
- 5846-1
- 5849-5
- 31208-2
Result Turnaround Time
1 day
Related Documents
For more information, please review the documents below
Specimen
Skin
Volume
Not provided
Minimum Volume
Not provided
Container
Viral transport media
Collection Instructions
Collect vesicle fluid or swab, tissue, or skin scrapings. Swab should be rolled in base of fresh vesicle to obtain cells. Transfer to viral transport media immediately and refrigerate.
Patient Preparation
Collect vesicle specimen during first 3 days of rash.
Storage Instructions
Immediately transfer specimen to viral transport media and refrigerate.
Causes for Rejection
Bone marrow, CSF, or whole blood. Calcium alginate, eSwab, dry or wood swabs.
Stability Requirements
| Temperature | Period |
|---|---|
| Room Temperature | Unacceptable |
| Refrigerated | 48 hours |
| Frozen | Unacceptable |