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West Nile Virus (WNV) NAT

Test Code: 30825

A special account is required to order pre-transplant testing. Contact Client Services or your account executive to set up a pre-transplant account to order this assay. Specimens should not be collected until after account has been created.

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Clinical and Procedure
Clinical Utility

The Procleix WNV Assay is a qualitative in vitro nucleic acid assay system for the detection of West Nile Virus (WNV) RNA in plasma specimens from individual human donors, including volunteer donors of whole blood and blood components, and other living donors. It is not intended for use on cord blood specimens. This assay is not intended for use as an aid in the diagnosis of West Nile Virus infection.

About West Nile Virus

WNV is a mosquito-borne flavivirus that is associated with human disease ranging from mild flu-like symptoms to severe neurological disease.1,2 Most WNV infections are asymptomatic and approximately 20% lead to a mild illness known as West Nile virus fever. Less than 1% of infections are estimated to cause serious neurological disease, with advanced age being the most significant risk factor.3

In most human infections, WNV multiplies to a relatively low level producing a transient viremia that can be detected in whole blood, plasma, and serum. Current diagnostic methods for WNV include Immunoglobulin M (IgM) enzyme immunoassays, Plaque Reduction Neutralization assays, and nucleic acid testing (NAT) methods. IgM antibody can be detected in serum or cerebrospinal fluid (CSF) collected within eight days of illness onset but NAT methods are capable of detecting infection prior to the presence of antibodies during the viremic phase. Because serologically based assays detect host immune response after this primary viremic phase and IgM can remain in the body for long periods of time, these tests may not be appropriate for blood screening.3,7

Screening of whole blood donations with NAT has been in place in the United States since early 1999 and licenses were granted for HIV-1 and HCV screening in 2002.16 The Procleix WNV Assay uses the same technology as the Procleix HIV-1/HCV Assay to detect WNV RNA and has been utilized in the United States for prospective blood screening since June 19, 2003 and was licensed in 2005.


The Procleix WNV Assay involves three main steps, which take place in a single tube: sample preparation; WNV RNA target amplification by Transcription-Mediated Amplification (TMA)26; and detection of the amplification products (amplicon) by the Hybridization Protection Assay (HPA)18. Test performed by VRL Eurofins, 6933 S. Revere Parkway, Centennial, CO 80112. This test has been cleared or approved for diagnostic use by the U.S. Food and Drug Administration. See package insert for more information

Turnaround Time

Within 24 hours from receipt of specimen.

Specimen Information
Specimen Type Order Code CPT Code NY Approved Volume Assay Range Special Instructions
Plasma (1) 30825 87797 Yes

2 mL (min 1 ml)


  • Collect whole blood in an EDTA, lavender top tube. Whole blood in ACD, Lithium Heparin, Sodium Citrate, or Sodium Heparin tubes are also accepted. Do not freeze whole blood.
  • Sample sent in original vacutainer tube can be shipped ambient and must be received within 72 hours.
  • If not shipping in original container, centrifuge and transfer 2 mL (min 1 mL) of the plasma to a sterile, screw top tube. Can be shipped refrigerated when received within 8 days or frozen received within 270 days.

All specimens must be labeled with patient's name and collection date. A Viracor/VRL Eurofins Pre-Transplant test requisition form must accompany each specimen. Multiple tests can be run on one specimen. Ship specimens FedEx Priority Overnight® to: VRL Eurofins, 6933 S. Revere Parkway, Centennial, CO 80112

Causes for Rejection

Whole blood frozen, specimens beyond their acceptable length of time from collection as listed in the specimen handling, or specimen types other than those listed.



Specimens are approved for testing in New York only when indicated in the Specimen Information field above. The CPT codes provided are based on VRL Eurofins' interpretation of the American Medical Association's Current Procedural Terminology (CPT) codes and are provided for informational purposes only. CPT coding is the sole responsibility of the billing party. Questions regarding coding should be addressed to your local Medicare carrier. VRL Eurofins assumes no responsibility for billing errors due to reliance on the CPT codes illustrated in this material.


West Nile Package Insert

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