Dermal lesion swab submitted in viral transport medium
Keep specimen at 4C
Specimen Collection from Dermal Lesions: Cells and fluid from fresh vesicles are superior to specimens prepared from other lesion types (e.g vesicles >> pustules >> ulcers >> crusts) for direct antigen detection, PCR and viral culture. Uncap the vesicle with a sterile needle or scalpel blade and use a sterile rayon or Dacron tipped, plastic shafted swab to vigorously swab the base of the lesion to obtain infected epithelial cells. To facilitate binding of the cellular material to the swab, the swab can be premoistened with sterile saline. Be certain to express the excess liquid from the swab before attempting to collect the specimen. For ulcers, use a swab to remove pus without disrupting the lesion base, and then use a fresh sterile swab to vigorously swab the base of the lesion to obtain cells. Crusted lesions should have the crust removed and discarded before collection of cells from the lesion base. NOTE: The yield of VZV from a crusted lesion is quite low for rapid antigen and culture-based tests and moderate for PCR, so the utility of collecting specimens from this type of lesion should be strongly considered. The swab should be immediately placed in viral transport medium and sent to the Clinical Virology Laboratory.
Swab specimens not received in viral transport medium or received in bacteriological transport medium are discouraged. DO NOT USE CALCIUM ALGINATE OR WOODEN SHAFT SWABS FOR COLLECTION OF SPECIMENS; ONLY USE DACRON OR RAYON TIPPED SWABS ON PLASTIC OR METAL SHAFTS.
Amplification and detection of VZV DNA glycoprotein B ORF 62 gene using TaqMan real-time PCR technology. This test is performed pursuant to an agreement with Roche Molecular Systems, Inc.
If positive, results are reported as varicella-zoster virus DNA detected.
Negative or no varicella-zoster virus DNA detected
Clinical Utility: Test can be used on children and adults with primary (chicken pox or varicella) or recurrent herpes zoster (shingles) infections. Teens & adults are at risk for more severe disease with pneumonia following chicken pox. Immunocompromised hosts and newborns are at risk for life-threatening pneumonia, encephalitis, hepatitis, and progressive-disseminated varicella. The elderly and immunocompromised are at risk for recurrent herpes zoster.