Measles Virus Qualitative PCR

The UW Clinical Virology Laboratory within the Department of Laboratory Medicine and Pathology utilizes a laboratory-developed assay on the Panther Fusion® platform for the rapid detection and differentiation of active wild-type measles infection versus recent vaccination, using real-time PCR.

The assay targets the nucleocapsid (N) gene, enabling detection of both wild-type measles virus and vaccine strain. Differentiation between wild-type and vaccine-associated strains is achieved using strain-specific primers and probes, allowing for selective amplification and detection of each target.

Results are reported qualitatively as Detected or Not Detected. For specimens with detectable viral RNA, a semi-quantitative assessment is provided through reporting of the PCR cycle threshold (Ct) value, which reflects the relative amount of target nucleic acid present in the sample. Lower Ct values correspond to higher viral loads, whereas higher Ct values indicate lower levels of viral RNA.

Ordering requirements:

For UW orders (any patient with a "U#" MRN), this test requires approval from the on-call Laboratory Medicine Resident (LMR) to help coordinate appropriate testing.

For outside clients, no approval is required.

Swabs:

Storage stability:

• Sample may be stored at 2 to 8°C for up to 72 hours of collection.
• Ship immediately to lab at 2 to 8°C (ice pack).
• If collection to receipt in the lab will exceed 72 hours freeze at -10°C or colder and ship on dry ice.
• Important: Do not freeze/thaw.

Urine:

Storage stability:

• Sample may be stored at 2-8°C (ice pack) for up to 48 hours from collection.
• Send urine at 2-8°C (ice pack) within 48 hours of collection.
• If collection to receipt in the lab will exceed 48 hours freeze at -10°C or colder and ship on dry ice.
• Important: Do not freeze/thaw.