Lab Dept:

Serology

Test Name:

WEST NILE VIRUS IGG/IGM ANTIBODY, CSF

General Information

Lab Order Codes:

WNVC

Synonyms:

Arbovirus Ab; Flavivirus Ab; Viral Encephalitis; WNV Ab; Mosquito borne encephalitis

CPT Codes:

86788 - West Nile Virus, IgM
86789 - West Nile Virus, IgG

Test Includes:

West Nile Virus IgG Antibody and West Nile Virus IgM Antibody

Logistics

Test Indications:

Preferred test for the laboratory diagnosis of WNV meningitis or encephalitis.

Lab Testing Sections:

Serology - Sendouts

Referred to:

Mayo Medical Laboratories (MML Test: WNC)

Phone Numbers:

MIN Lab: 612-813-6280

STP Lab: 651-220-6550

Test Availability:

Daily, 24 hours

Turnaround Time:

1 – 4 days, test setup Monday-Friday (June-October) and Monday, Wednesday, Friday (November-May)

Special Instructions:

N/A

Specimen

Specimen Type:

CSF

Container:

Sterile container

Draw Volume:

0.5 mL (Minimum: 0.4 mL) CSF

Processed Volume:

Same as Draw Volume

Collection:

Routine CSF collection

Special Processing:

Lab Staff: Store specimen in refrigerator. Ship at refrigerated temperatures. Forward promptly.

Patient Preparation:

None

Sample Rejection:

Specimens other than CSF (spinal fluid); mislabeled or unlabeled specimens

Interpretive

Reference Range:

IgG: Negative

IgM: Negative

Critical Values:

N/A

Limitations:

Test results should be used in conjunction with a clinical evaluation and other available diagnostic procedures.

The significance of negative test results in immunosuppressed patients is uncertain.

False-negative results due to competition by high levels of IgG, while theoretically possible, have not been observed.

WNV antibody results for CSF should be interpreted with caution.  Complicating factors include low antibody levels found in CSF, passive transfer of antibody from blood, and contamination via bloody taps.

Methodology:

Enzyme Immunoassay (EIA)

References:

Mayo Medical Laboratories Web Page November 2015

Updates:

11/19/2015: Method update, previously listed as ELISA.