Reference IntervalNormal range/expected value(s) for a specific disease state. May also include abnormal ranges.
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 DataBackground information for test. May include disease information, patient result explanation, recommendations, details of testing, associated diseases, explanation of possible patient results.
This test is intended to be used as a semi-quantitative means of detecting West Nile virus-specific IgM in CSF specimens in which there is a clinical suspicion of West Nile virus infection. This test should not be used solely for quantitative purposes, nor should the results be used without correlation to clinical history or other data. Because other members of the Flaviviridae family, such as St. Louis encephalitis virus, show extensive cross-reactivity with West Nile virus, serologic testing specific for these species should be considered.
The detection of antibodies to West Nile virus in cerebrospinal fluid may indicate central nervous system infection. However, consideration must be given to possible contamination by blood or transfer of serum antibodies across the blood-brain barrier.
This test was developed and its performance characteristics determined by ARUP Laboratories. It has not been cleared or approved by the US Food and Drug Administration. This test was performed in a CLIA certified laboratory and is intended for clinical purposes.
Compliance Category
Laboratory Developed Test (LDT)
NoteAdditional information related to the test.
Hotline History
N/A
CPT CodesThe American Medical Association Current Procedural Terminology (CPT) codes published in ARUP's Laboratory Test Directory are provided for informational purposes only. The codes reflect our interpretation of CPT coding requirements based upon AMA guidelines published annually. CPT codes are provided only as guidance to assist clients with billing. ARUP strongly recommends that clients confirm CPT codes with their Medicare administrative contractor, as requirements may differ. CPT coding is the sole responsibility of the billing party. ARUP Laboratories assumes no responsibility for billing errors due to reliance on the CPT codes published.
* 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.
AliasesOther names that describe the test. Synonyms.