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Test Code WNVBL West Nile Virus, RNA, PCR, Molecular Detection, Blood


Specimen Required


Container/Tube: Lavender top (EDTA)

Specimen Volume: 1 mL

Collection Instructions:

1. Invert several times to mix blood.

2. Send whole blood specimen in original tube. Do not aliquot.


Useful For

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.

Reporting Name

West Nile Virus RNA, PCR, Blood

Specimen Type

Whole Blood EDTA

Specimen Minimum Volume

See Specimen Required

Specimen Stability Information

Specimen Type Temperature Time Special Container
Whole Blood EDTA Refrigerated 7 days

Reject Due To

All specimens will be evaluated at Mayo Clinic Laboratories for test suitability.

Reference Values

Negative

Reference values apply to all ages.

Supportive Data

The following validation data supports the use of this assay for clinical testing.

 

Accuracy/Diagnostic Sensitivity and Specificity:

Accuracy studies were performed by testing negative clinical specimens with whole viral genomic RNA for lineages 1 and 2 near the limit of detection (LOD) and yielded greater than or equal to 97% sensitivity and specificity.

 

Analytical Sensitivity/LOD:

The lower LOD of this assay is 1 to 5 target copies/mcL of RNA extract for serum, urine, and spinal fluid and 27 to 60 copies/mcL for EDTA whole blood.

 

Precision:

Inter-assay and intra-assay precisions are 100%.

 

Specificity:

A panel of 42 organisms that can be found in the specimen types acceptable for this assay, as well as closely-related viruses (eg, dengue types 1-4, Japanese encephalitis virus, hepatitis E virus, Murray Valley encephalitis virus, St. Louis encephalitis virus, tick-borne encephalitis virus, yellow fever virus, Zika virus) and those that can cause a similar clinical syndrome were tested by this assay. No cross-reacting positive results were noted.

 

Reportable Range:

This is a qualitative assay, and the results are reported as either negative or positive for targeted West Nile virus.

Day(s) Performed

Monday through Friday

Report Available

Same day/1 to 5 days

Specimen Retention Time

1 week

Performing Laboratory

Mayo Clinic Laboratories in Rochester

CPT Code Information

87798

LOINC Code Information

Test ID Test Order Name Order LOINC Value
WNVBL West Nile Virus RNA, PCR, Blood 34460-6

 

Result ID Test Result Name Result LOINC Value
608438 West Nile Virus RNA, PCR, Blood 34460-6

Forms

If not ordering electronically, complete, print, and send a Microbiology Test Request (T244) with the specimen.