West Nile Virus, RNA, PCR, Molecular Detection, Blood

Casandra

Casandra Test Code MC70363Version 1 (DRAFT)

Performing Lab

Lab Mayo Clinic LabLab Test ID WNVBLCPT Code 87798

West Nile Virus, RNA, PCR, Molecular Detection, Blood

Clinical Use

Use

Rapid testing for West Nile virus (WNV) RNA (lineage 1 and lineage 2). An adjunctive test to serology for detection of early WNV infection (ie, first few days after symptom onset), with blood specimens potentially providing a greater sensitivity than other sources for WNV RNA detection. Not intended for screening asymptomatic individuals; use only in patients with signs and symptoms of WNV disease.

Special Instructions

Refer to Meningitis/Encephalitis Panel Algorithm and Mosquito‑borne Disease Laboratory Testing for testing algorithm guidance. If not ordering electronically, complete and send a Microbiology Test Request (T244) with the specimen.

Limitations

Sensitivity is highly dependent on timing relative to illness onset; greatest utility is during the first few days of symptom onset. A negative result does not exclude WNV infection—results should be interpreted alongside clinical findings and serologic testing. The assay detects both viable and nonviable virus, and performance depends on viral load, which may not correlate with cell culture.

Test Details