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Lab Dept:
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Microbiology/Virology
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Test Name:
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VARICELLA ZOSTER VIRUS DIRECT FA
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General Information
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Lab Order Codes:
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DVZV
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Synonyms:
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VZV Direct FA; VZV DFA; Herpes Zoster FA; FA for VZV
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CPT Codes:
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87290 - Infectious agent antigen detection by immunofluorescent technique; Varicella zoster virus
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Test Includes:
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Detection of Varicella Zoster virus antigen in skin lesions and vesicles, using direct immunofluorescence. Viral culture must be ordered with this test. Refer to Viral Culture
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Logistics
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Lab Testing Sections:
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Virology
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Phone Numbers:
Minneapolis:
Saint Paul:
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612-813-5806
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651-220-6555
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Test Availability:
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Daily, 24 hours
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Turnaround Time:
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Specimens must arrive by noon for same day results. All specimens received after that time will be held until the next working day for completion
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Special Instructions:
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● Do Not use calcium alginate swabs.
● Requisition must state specific site of specimen and date/time of collection.
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Specimen
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Specimen Type:
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Swab of vesicular skin lesion
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Container:
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Swab transport system, viral transport media (available in Microbiology)
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Volume:
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1 swab, 1 smear
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Collection:
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1. Wash vesicles with sterile saline.
2. Unroof the vesicle and absorb vesicular fluid into a dry swab.
3. Vigorously scrape base of freshly exposed lesion with swab to obtain cells, which contain virus.
4. Maintain sterility and forward promptly at ambient temperature.
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Special Processing:
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Place swab into viral transport media (VTM). Swabs should remain in VTM for higher yield of cells
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Transport/Storage:
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Transport to the Microbiology Lab immediately. Store at refrigerated temperatures. If specimens cannot be transported to the laboratory immediately, place in viral transport media (VTM)and refrigerate. Swabs should remain in the VTM.
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Sample Rejection:
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Specimen with a transit time exceeding 2 hours after collection; specimen not submitted in appropriate transport container; improperly labeled specimen; insufficient volume; external contamination. If an unacceptable specimen is received, the physician or nursing station will be notified and another specimen will be requested before the specimen is discarded.
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Interpretive
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Reference Range:
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No varicella zoster virus detected by DFA
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Limitations:
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● A negative result does not eliminate the possibility of varicella zoster virus.
● DFA testing should be performed simultaneously with culture to increase sensitivity.
● Results are collection dependent. Specimen should be collected early in course of disease; specimens collected later rarely yield virus. DFA cannot be interpreted if insufficient cells are present to evaluate
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Methodology:
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Direct Fluorescent Antibody
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References:
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Cook, JH, and M Pezzlo (1992). Specimen receipt and accessioning. Section 1. Aerobic bacteriology, 1.2.1-4. In HD Isenberg (ed) Clinical Microbiology Procedures Handbook. American Society for Microbiology, Washington DC
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Miller, J Michael (1999) A Guide To Specimen Management in Clinical Microbiology, American Society for Microbiology, Washington DC
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Miller, J Michael, and HT Holmes (1999) Specimen Collection, Transport, and Storage In PR Murray et al, (ed), Manual of Clinical Microbiology, 7th edition, American Society for Microbiology, Washington DC, pg 33-104
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