West Nile Virus/ St. Louis Encephalitis IgM Antibody

WSLH Department: CDD - Communicable Disease Division
WSLH Test Code: SS02241
Availability: Test is performed weekly
Turn-around Time: 2-8 days
Recommended Uses: Serodiagnosis of a recent infection with any of these agents in individuals with symptoms of arbovirus infection.
Contraindications: Testing will not be performed as a screening test or on patients without symptoms of WNV or SLE infection.
Additional Tests Performed:
Patient Preparations: Specimens should be collected in the acute phase of illness.
Specimen Requirements: 1-3 ml serum or 8.5 ml SST vacutainer tube, no additives; CSF, minimum 2 ml. CSF must be accompanied by serum specimen
Specimen Handling & Transport: Specimens must be stored refrigerated (2-8C) and transported with frozen cool packs and should be received within 48 hours of collection.
Collection Kit/Container: Serology Specimens
Sterile Transfer Tube
Collection Instructions:
Unacceptable Conditions:
Requisition Form: CDD Requisition Form B
Required Information: Clinical information regarding symptoms and onset must be provided. Laboratory regulations require the following minimum information to be provided on the requisition form for a specimen to be accepted for testing: Patient name or unique identifier; date and time of collection, patient date of birth and sex, specimen type/site of collection, test request(s), clinician name and UPIN, and address for reporting results. Please be certain that name/identifier on the form matches that on the specimen label.
Results Include: ** Negative: Test on single acute phase CSF or serum does not rule out infection. Lack of serological evidence of infection may reflect testing of acute phase specimen(s) obtained before development of an antibody response.

** Equivocal: It is recommended that a serum specimen be collected in 2-3 weeks for follow-up testing.

** Presumptive Positive: Serologic evidence for recent infection with West Nile virus or St. Louis Encephalitis virus.

** Non-Specific: It is recommended that a serum specimen be collected in 2-3 weeks for follow-up testing.
Limitations: Cross-reaction may occur between the arboviruses. Negative results on a single acute phase specimen do not rule out infection, as specimen may have been obtained prior to the development of an antibody response.
Additional Tests Recommended: Enterovirus PCR, HSV, or other individual arboviral agents (LAC, POW, JC, or EEE) are also recommended.
Additional Comments: The MIA test methodology was developed at the CDC and validated at WSLH. It has not been cleared or approved by the U.S. Food and Drug Administration. Testing is performed twice weekly. Please contact the laboratory for information about out-of-season arbovirus testing.
Methodology: Microsphere Immunoassay (MIA)
Includes: Qualitative IgM testing for West Nile Virus (WNV) Encephalitis and St. Louis Encephalitis (SLE) viruses.
CPT Code: 86788, 86653
Price: $134.00
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