Test Directory

• West Nile Virus, IgM
• West Nile Virus, IgG

This test is indicated for use as an aid to the diagnosis of West Nile virus encephalitis. WNV IgM antibodies typically appear three to eight days after illness onset and persist 30 to 90 days (but can persist up to 500 days). WNV IgG antibodies appear shortly after IgM antibodies and persist greater than 500 days. Due to cross-reactivity with other flaviviruses, confirmation by neutralizing antibody assay may be recommended.

Specimen Type: Serum

Collection Container: Gold Top, Serum Separator

Alternate Collection Container: Red Top, Plain

Desired Specimen Volume: 1 mL 

1. Collect a gold top, serum separator tube via venipuncture.

1. Separate serum from cells.
2. Transfer 1 mL of serum to a clear aliquot tube (screw cap).

Transport to the laboratory refrigerated. 

• Gross contamination
• Severe hemolysis
• Icteric serum
• Lipemic serum
• Quantity not sufficient for analysis

See patient report.

The performance of this assay has not been established for screening the general population. Testing should only be performed on patients with clinical symptoms consistent with WNV encephalitis. Serological cross-reactivity across the flavivirus group is common (i.e., between Dengue virus, Japanese encephalitis virus, St. Louis encephalitis virus, yellow fever virus and others).

• Flavivirus
• Mosquito-borne
• Vectorborne
• West Nile Virus, IgG and IgM
• West Nile Virus, Serology
• WNV Antibody