West Nile Virus IgM, CSF




Test Mnemonic

CWESTM

CPT Codes

  • 86788 - QTY (1)

LOINC ®

39573-1

Includes

  • West Nile Virus IgM

Performing Laboratory

ARUP


Specimen Requirements

Volume Type Container Collect Temperature Transport Temperature Special Instructions
2 mLCerebrospinal fluid (CSF)Sterile container Refrigerated 

Minimum Specimen Requirements

Volume Type Container Collect Temperature Transport Temperature Special Instructions
0.3 mL     

Stability

Environmental Condition Description
Ambient8 hours
Refrigerated2 weeks
Frozen1 year (Avoid repeated freeze/thaw cycles)

Days Performed

Sun, Tues, Fri

Turnaround Time

2 - 7 days

Methodology

Name Description
Semi Quantitative Enzyme Linked Immunosorbent Assay 

Reference Range

West Nile Virus IgM
Sex Age From Age To Type Range Range Unit
       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. 

Special Info

Bacterially contaminated, heat-inactivated, hemolyzed or xanthochromic specimens will be rejected. If possible, specimens from New York clients will be sent out to a New York DOH approved laboratory.

Clinical Info

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.