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EndemicSER · SerologyWNVIGMArboviral surveillance pack
West Nile virus IgM
West Nile virus
Last reviewed 2026-08-13
Public health significance
The endemic arbovirus that still fills neuroinvasive case counts every summer.
Specimen types
Serum, CSF
Method
IgM EIA, often with PRNT confirmation
CLIA / validation
High complexity serology. Document cross-reactivity with other flaviviruses.
Interpretation
Presumptive positive / Negative / Equivocal. PRNT is frequently required before a case is closed.
Reflex / referral
PRNT or plaque-reduction neutralization at the public health or CDC lab.
Quality control
Kit controls plus a characterized presumptive-positive.
Reportability
Neuroinvasive WNV is reportable.
HL7 / ELR
IgM LOINC (e.g. 31797-7) plus interpretation. PRNT may ride as NTE or a second OBX.
Sources
CDC WNV diagnostic testing; APHL arbovirus resources.