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Test Code
WNVBL
Test Name
West Nile Virus, RNA, Whole Blood
CPT Codes
87798
Expected Turnaround Time
1 - 5 days
Clinical Utility
Rapid testing for West Nile virus (WNV) RNA (lineage 1 and lineage 2)

An adjunctive test to serology for detection of early WNV infection (ie, first few days after symptom onset), with blood specimens potentially providing a greater sensitivity than other sources for WNV RNA detection

This test should not be used for screening asymptomatic individuals and should only be used to test patients with signs and symptoms of WNV disease.
Specimen and Container Info

Specimen Type: Whole Blood

  

Collection Container: Lavender Top (EDTA)

Desired Specimen Volume: 1 mL
Collection Instructions
  1. Collect a lavender top (EDTA) tube via venipuncture.
  2. Invert several times to mix blood.
Processing and Submission Instructions
  1. Transport 1 mL of whole blood in the original collection container. Do not aliquot.
Transport Instructions

Transport to the laboratory refrigerated. 
Stability Requirements

Refrigerated

7 days
Methodology
Real Time Polymerase Chain Reaction
Reference Intervals

See patient report.
Limitations

The sensitivity of the assay is very dependent upon the time of illness onset in which the specimen is collected. Polymerase chain reaction testing has the greatest utility when used within the first few days of symptom onset.

A negative test does not exclude infection with West Nile virus. Therefore, the results obtained should be used in conjunction with clinical findings and serologic test results to make an accurate diagnosis.

This assay detects both viable and nonviable virus. Test performance depends on viral load in the specimen and may not correlate with cell culture performed on the same specimen.
Alternate Names
  • Arbovirus
  • Flavivirus
  • Mosquito Borne Encephalitis
  • Viral encephalitis
  • West Nile PCR
  • West Nile Virus (WNV)
  • WNV PCR
Reference Lab
Mayo Clinic Laboratories
Testing Schedule
Routine, 5 times per week
The American Medical Association (AMA) Current Procedural Terminology (CPT) codes published by HNL Lab Medicine are guidelines and are intended for informational purposes only. CPT coding is the exclusive responsibility of the billing entity. View the Terms.
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