West Nile Virus Antibody, IgM, Blood (Referred Out) – Saskatoon

Overview

Description

Ordering recommendation

• IgM should only be requested on symptomatic patients

Specimen Information

Specimen types accepted

• Serum

Specimen collection container

• Preferred collection container: Gold (Gel) tube
• Alternative collection container: Red (non-gel); not preferred

Required volume

• Optimal volume: 4.5 mL full collection tube
• Minimum volume: 2.0 mL
  • (Submitting the minimum volume makes it impossible to repeat the test or perform confirmatory/reflex testing. In some situations, a minimum volume may require a second collection.

Testing Information

Clinical interpretation

• This should be the initial test for diagnosis of suspect West Nile Virus

Performance

Days/times performed

Availability	Shipped daily Monday to Sunday
Testing site	Referred out by St. Paul’s Hospital Laboratory to Roy Romanow Provincial Laboratory

 

Maximum laboratory time

Results reporting

• Three day turnaround time by testing laboratory
• Positive results are reported to the Medical Health Officer

Reflex testing

• West Nile Virus IgG and West Nile Virus IgG Avidity tests performed on all West Nile Virus IgM positive specimens

Last Updated: January 9, 2026