Zika Virus Antibody, IgM (Sendout)

Useful For: Screening for presence of IgM-class antibodies to Zika virus. This assay should be used in patients presenting at least 2 weeks post-symptom onset or last possible exposure to Zika virus. Reverse transcription-polymerase chain reaction (RT-PCR) for Zika virus RNA detection should be ordered in patients with less than 2 weeks of symptoms or postexposure. For Zika Virus RT-PCR, refer to separate test guide #991.

• This test is not intended for medical-legal use.
• This test is not recommended for asymptomatic couples attempting conception.

Testing Algorithm:

• Mayo Clinic Laboratories: Assessment for Zika Virus Infection

Interpretation:

Presumptive Zika Positive: IgM-class antibodies to Zika virus (ZIKV) detected. This is a preliminary result and does not confirm evidence of ZIKV infection. Confirmatory testing may be required as determined by your local health department. False-positive results may occur in patients with other current or prior flavivirus infections (eg, dengue virus). For patients with less than 7 days of symptoms or last possible exposure to ZIKV, reverse transcription-polymerase chain reaction (RT-PCR) for ZIKV on serum and urine is recommended. A positive ZIKV RT-PCR result on either specimen is confirmatory for ZIKV infection.

Other Flavivirus Positive: Antibodies to a flavivirus, not ZIKV, were detected. Consider targeted testing for IgM-class antibodies to dengue and/or West Nile viruses as appropriate, taking into consideration patient exposure and presentation.

Negative: No evidence of IgM-class antibodies to ZIKV. For specimens collected less than 7 days post symptom onset or possible ZIKV exposure, RT-PCR for ZIKV on serum and urine to exclude a false-negative ZIKV IgM result is recommended. For symptomatic patients with travel to dengue endemic areas, testing for IgM antibodies to dengue virus is also recommended.

Outside Laboratories: Centrifuge sample and transfer serum to a separate plastic vial. Freeze serum at -20°C.

Stability: Frozen (required): 30 days; Refrigerated: Unacceptable; Ambient: Unacceptable.

Reject Due to: Gross hemolysis, gross lipemia, gross icterus, heat-inactivated specimen.

Centrifuge sample and transfer serum to a separate plastic vial. Freeze serum at -20°C.

Sendouts:

• Order Mayo Test: VZIKM.
• Interfaced: Yes.

Stability: Frozen (required): 30 days; Refrigerated: Unacceptable; Ambient: Unacceptable.

Reject Due to: Gross hemolysis, gross lipemia, gross icterus, heat-inactivated specimen.