West Nile Virus, RNA, PCR, Molecular Detection, Serum
Use
This test is useful for rapid testing for West Nile virus (WNV) RNA (lineage 1 and lineage 2) using serum specimens. It serves as an adjunctive test to serology for detection of early WNV infection, especially within the first few days after symptom onset, where specific antibodies to the virus are not yet present. It is particularly valuable for testing patients showing signs and symptoms of WNV disease and is not recommended for screening asymptomatic individuals.
Special Instructions
This test should not be used for screening asymptomatic individuals and should only be ordered for patients exhibiting signs and symptoms of West Nile Virus disease. If not ordering electronically, providers should complete, print, and send a Microbiology Test Request (T244) with the specimen.
Limitations
The sensitivity of the assay is greatly dependent on the timing of specimen collection with respect to symptom onset. Whole blood has demonstrated improved sensitivity over serum for detecting WNV RNA. A negative test does not rule out WNV infection; results should be correlated with clinical findings and serologic test data for accurate diagnosis. PCR detects both viable and nonviable viruses, and the assay's performance is dependent on viral load, which may not correlate with cell culture results.
New York Approved
Methodology
PCR-based (RT-PCR)
Biomarkers
LOINC Codes
- 32361-8
- 32361-8
Result Turnaround Time
1-5 days
Related Documents
For more information, please review the documents below
Specimen
Serum
Volume
0.5 mL
Minimum Volume
0.3 mL
Container
Sterile container
Collection Instructions
Within 2 hours of collection, centrifuge and aliquot serum into a sterile container. Serum specimens not aliquoted from the serum gel collection tube into a sterile container will be rejected.
Causes for Rejection
Gross hemolysis, heat-inactivated specimen
Stability Requirements
| Temperature | Period |
|---|---|
| Refrigerated | 7 days |
| Frozen | 7 days |