ARUP's Laboratory Test Directory

West Nile Virus Antibodies, IgG and IgM by ELISA, Serum : 0050226

Mnemonic: WNILE SER

Methodology: Semi-Quantitative Enzyme-Linked Immunosorbent Assay
Performed: Tue, Fri
Reported: 1-8 days
Specimen Required: Collect: Serum separator tube.

Specimen Preparation: Separate serum from cells ASAP or within 2 hours of collection. Transfer 1 mL serum to an ARUP Standard Transport Tube. (Min: 0.15 mL) 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."

Storage/Transport Temperature: Refrigerated.

Unacceptable Conditions: Plasma. Contaminated, heat-inactivated, hemolyzed, or severely lipemic specimens.

Stability (collection to initiation of testing): After separation from cells: Ambient: 48 hours; Refrigerated: 2 weeks; Frozen: 1 year (avoid repeated freeze/thaw cycles)
Reference Interval:
 
Test Number Components Reference Interval
0050234West Nile Virus Antibody, IgG by ELISA, Serum 1.29 IV or less: Negative - No significant level of West Nile virus IgG antibody detected.
1.30-1.49 IV: Equivocal - Questionable presence of West Nile virus IgG antibody detected.  Repeat testing in 10-14 days may be helpful.
1.50 IV or greater: Positive - Presence of IgG antibody to West Nile virus detected, suggestive of current or past infection. 
0050236West Nile Virus Antibody, IgM by ELISA, Serum 0.89 IV or less: Negative - No significant level of West Nile virus IgM antibody detected.
0.90-1.10 IV: Equivocal - Questionable presence of West Nile virus IgM antibody detected.  Repeat testing in 10-14 days may be helpful.
1.11 IV or greater: Positive - Presence of IgM antibody to West Nile virus detected, suggestive of current or recent infection. 
 
Interpretive Data: Refer to individual components for additional interpretive data.
CPT Code(s): 86789; 86788
Cross References: Arbovirus (West Nile Virus Antibodies, IgG & IgM by ELISA, Serum), Flavivirus (West Nile Virus Antibodies, IgG & IgM by ELISA, Serum), Mosquito borne encephalitis (West Nile Virus Antibodies, IgG & IgM by ELISA, Serum), Viral encephalitis (West Nile Virus Antibodies, IgG & IgM by ELISA, Serum)