Test is performed once a week 

3-14 days

Serodiagnosis of a recent Powassan 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 coma) with no other laboratory diagnosis; or the patient has a diagnosis of Guillain-Barr syndrome and no other laboratory diagnosis. 

Specimens should be collected in the acute phase of illness. 

N

Testing should not be performed as a screening test or on patients without symptoms of Powassan Encephalitis virus infection. 

1-3 ml serum or 8.5 ml SST vacutainer tube, no additives; CSF, minimum 2 ml. CSF must be accompanied by serum specimen.

Routine blood draw

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.

Specimens received without cold packs or dry ice. Specimens collected post mortem are unacceptable for testing.

Specimens should be stored at 2-8 °C, transported with a frozen cold pack, and should be received within 48 hours of collection. If specimens will not be tested for 3 or more days, they should be frozen at -20°C until ready for shipment and shipped on dry ice.

Category B Shipping  

This test is not eligible for fee-exempt courier service.

Monday-Friday 7:45 AM - 4:30 PM, Saturday 7:45 AM - 12:00 PM

** 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: An equivocal result was obtained. 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 Powassan Virus. ** Non-Specific: An equivocal result was obtained. It is recommended that a serum specimen be collected in 2-3 weeks for follow-up testing.

The Presumptive Positive result may be due to cross reactivity with other flavivirus serogroup virus. The Presumptive Positive results must be confirmed by plaque-reduction neutralization testing (PRNT). Equivocal and Non-Specific results will be confirmed with 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.

Testing for other arbovirus agents (JC, LAC, WNV/SLE, EEE) is recommended. WSLH test code SS02201 

IgM Antibody Capture Enzyme-Linked Immunosorbent Assay (MAC-ELISA)

Qualitative IgM antibody capture enzyme-linked immunosorbent assay for the detection of IgM antibodies in serum and cerebrospinal fluid (CSF) specific to Powassan Encephalitis virus.

Lab Developed Test – CDC Developed

Yes, with DHS approval only, 608-267-9003

1-800-862-1065 arbill@slh.wisc.edu