La Crosse Encephalitis IgM Antibody Print

WSLH Department: CDD - Communicable Disease Division
WSLH Test Code: SS02231
Availability: Test is performed weekly
Turn-around Time: 2-8 days
Recommended Uses: Serodiagnosis of a recent La Crosse Encephalitis virus infection. The test is indicated for use in patients with signs and symptoms of meningitis (fever headache and stiff neck) or encephalitis (fever, headache, and altered mental status ranging from confusion to come) with no other laboratory diagnosis, or the patient has a diagnosis of Guillain-Barre syndrome and no other laboratory diagnosis.
Contraindications: Testing will not be performed as a screening test or on patients without symptoms of La Crosse Encephalitis virus infection.
Additional Tests Performed:
Patient Preparations: Routine blood draw
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: Specimens should be collected in the acute phase of illness.
Unacceptable Conditions: Specimens must be stored refrigerated (2-8C) and transported with frozen cool packs.
Requisition Form: CDD Requisition Form B
Required Information: 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 La Crosse Encephalitis virus.

** Non-Specific: It is recommended that a serum specimen be collected in 2-3 weeks for follow-up testing.
Limitations: The Presumptive Positive result may be due to cross reactivity with other Members of the California serogroup viruses, such as California encephalitis, snowshoe hare and Jamestown Canyon viruses. The Presumptive Positive, Equivocal, and Non-Specific results must be confirmed by plaque-reduction neutralization testing (PRNT). The performance of this assay has not been established for ruling out diseases with similar symptoms, e.g., herpes simplex virus encephalitis, enterovirus encephalitis, bacterial meningitis, causes of non-infectious encephalitis, or post-infectious encephalitis. 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 and HSV PCR or antibody testing for other individual arboviral agents (WNV, SLE, JC, POW, or EEE) is also recommended.
Additional Comments: This test was developed and its performance characteristics determined by the CDC and validated at the WSLH. It has not been cleared or approved by the U.S. Food and Drug Administration. Testing is performed once weekly from May until November. Please contact the laboratory for information about out-of-season arbovirus testing. Specimens positive, equivocal, or non-specific for La Crosse Encephalitis Virus will be confirmed by PRNT at CDC.
Methodology: IgM Antibody Capture Enzyme-Linked Immunosorbent assay (MAC-ELISA)
Includes: Qualitative IgM antibody capture enzyme-linked immunosorbent assay for the detection of IgM antibodies in serum and cerebrospinal fluid (CSF) specific to LaCrosse Encephalitis virus.
CPT Code: 86651
Price: $145.00
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