West Nile Virus Antibody, IgM by ELISA, Serum
Also known as: WNILE IGM
Use
This test is intended to be used as a semi-quantitative means of detecting West Nile virus-specific IgM in serum specimens in which there is a clinical suspicion of West Nile virus infection. A positive result suggests current or recent infection with West Nile virus. It aids in the diagnosis of acute West Nile infection. However, due to cross-reactivity with other members of the Flaviviridae family such as St. Louis encephalitis virus, additional specific serologic testing may be necessary.
Special Instructions
Parallel testing is preferred, and convalescent specimens must be received within 30 days from receipt of the acute specimens. Mark specimens plainly as 'acute' or 'convalescent.'
Limitations
The test should not be used solely for quantitative purposes, nor should the results be used without correlation to clinical history or other data. Because of extensive cross-reactivity with other members of the Flaviviridae family, such as St. Louis encephalitis virus, serologic testing specific for these species should be considered. A false positive rate of 2-3% has been demonstrated with the Focus Diagnostics ELISA assay. Seroconversion between acute and convalescent sera is strong evidence of current or recent infection; significant change on two appropriately timed specimens, where both tests are done in the same laboratory, provides the best evidence for infection.
New York Approved
Methodology
Immunoassay (ELISA)
Biomarkers
LOINC Codes
- 38166-5
Result Turnaround Time
1-6 days
Related Documents
For more information, please review the documents below
Specimen
Serum
Volume
1 mL
Minimum Volume
0.15 mL
Container
ARUP Standard Transport Tube
Collection Instructions
Separate serum from cells ASAP or within 2 hours of collection. Transfer to ARUP Standard Transport Tube.
Storage Instructions
Refrigerated
Causes for Rejection
Bacterially contaminated, heat-inactivated, hemolyzed, icteric, lipemic, or turbid specimens.
Stability Requirements
| Temperature | Period |
|---|---|
| Room Temperature | 48 hours |
| Refrigerated | 2 weeks |
| Frozen | 1 year (avoid repeated freeze/thaw cycles) |