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Test Directory


West Nile Virus Antibodies (IgG, IgM), Serum

Order Name WEST NILE
Test Number: 3609525
Revision Date 10/05/2020
Test Name Methodology LOINC Code
West Nile Antibodies IgG
Enzyme Immunoassay 38997-3 
West Nile Antibodies IgM
Enzyme Immunoassay 38166-5 
Specimen Specimen Volume (min) Specimen Type Specimen Container Transport Environment
Preferred 1 mL (0.5) Serum Clot Activator SST Refrigerated or Frozen
Instructions Allow specimen to clot completely at room temperature. Separate serum or plasma from cells ASAP or within 2 hours of collection.
Stability After separation from cells: Ambient - 8 hours, Refrigerated - 48 hours, Frozen -1 month (avoid repeated freeze/thaw cycles).
Testing Schedule Seasonal. In season: Mon, Wed, Fri. Out of season: Tue, Thur 
Expected TAT 2-5 Days  
Clinical Use West Nile Virus is a flavivirus recently associated with an outbreak of encephalitis in the Eastern United States. West Nile Virus IgM is usually detectable by the time symptoms appear, but IgG may not be detectable until day 4 or day 5 of illness. Antibodies induced by West Nile Virus infection show extensive crossreactivity with other flaviviruses, including Dengue Fever Virus and St. Louis Encephalitis Virus. 
CPT Code(s) 86788, 86789
Lab Section Immunology - Serology