Ordering Recommendation

Not recommended as a stand-alone test. Refer to Arbovirus Antibodies, IgG and IgM, Serum (2001594).

New York DOH Approval Status

This test is New York state approved.

Specimen Required

Patient Preparation

Serum separator tube. Also acceptable: Plain red.

Specimen Preparation

Separate serum from cells ASAP or within 2 hours of collection. Transfer 1 mL serum to an ARUP Standard Transport Tube. (Min: 0.4 mL) Parallel testing is preferred and convalescent specimens must be received within 30 days from receipt of acute specimens. Mark specimens plainly as "acute" or "convalescent."

Storage/Transport Temperature


Unacceptable Conditions

Contaminated, hemolyzed, or severely lipemic, specimens.


After separation from cells: Ambient: 48 hours; Refrigerated: 2 weeks; Frozen: 1 year (avoid repeated freeze/thaw cycles)


Semi-Quantitative Indirect Fluorescent Antibody/Semi-Quantitative Enzyme-Linked Immunosorbent Assay


Tue, Fri


1-5 days

Reference Interval

Test Number
Reference Interval
  St. Louis Encephalitis Ab, IgG, Serum Less than 1:16
  Calif Encephalitis Antibody IgG Less than 1:16
  Eastern Equine Enceph Ab, IgG Less than 1:16
  Western Equine Enceph Ab, IgG, Serum Less than 1:16
  West Nile Virus Ab, IgG, Ser 1.29 IV or less

Interpretive Data

Component Interpretation
West 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.

Compliance Category



Hotline History


CPT Codes

86651; 86652; 86653; 86654; 86789


Component Test Code* Component Chart Name LOINC
0050234 West Nile Virus Ab, IgG, Ser 38997-3
0050507 St. Louis Encephalitis Ab, IgG, Serum 10906-6
0050508 Calif Encephalitis Antibody IgG 10904-1
0050509 Eastern Equine Enceph Ab, IgG 10896-9
0050514 Western Equine Enceph Ab, IgG, Serum 6957-5
* Component test codes cannot be used to order tests. The information provided here is not sufficient for interface builds; for a complete test mix, please click the sidebar link to access the Interface Map.


  • Encephalitis Antibodies
Arbovirus Antibodies, IgG, Serum