West Nile/St. Louis Encephalitis IgM

Brief Description

The WN/SLE duplex MIA procedure is a replacement for the WN and SLE MAC-ELISAs test with a single, equally sensitive, faster test. It is an immunological capture assay for the qualitative determination of IgM-class antibodies to the WN and SLE viruses.  These viruses co-circulate in parts of the US and are routinely tested concurrently.

Laboratory Unit



Microsphere-based immunologic assay (MIA)

Specimen Collection

Cerebrospinal Fluid (CSF):

Collect in a sterile container.


Cerebrospinal fluid should be stored frozen (-20°C or colder) and shipped with dry ice.

Acceptable Specimen Type(s)

Cerebral Spinal Fluid (CSF)

Test Request

Possible Results

  • Positive
  • Negative
  • Unsatisfactory

Reference Range


Unacceptable Conditions

  • Missing testing requisition
  • Missing minimum of 2 patient identifiers
  • Improper labeling
  • Improper storage/transport of specimen
  • No specimen received (empty collection tube).
  • Wrong specimen type

Interfering Substances


Result Reported

5-7 business days


No charge

LOINC/Order Codes

31703-2 (Order code: 1590)