Although in the past, Zika virus testing in the US has been mainly performed by the CDC and in various public health laboratories, there has recently been an increase in the number of commercial and hospital-based laboratories that have received the FDA’s EUA for the detection of Zika virus in serum and urine. Most of these EUA approvals have been for molecular tests (NATs) that identify Zika virus RNA. In addition, serological assays for Zika virus-reactive antibodies, such as the Zika MAC ELISA, have also been approved.
Emergency Use Authorization (EUA): On February 26, 2016, the Secretary of Health and Human Services (HHS) declared that circumstances exist justifying the authorization of the emergency use of in vitro diagnostics for the detection of Zika virus and/or diagnosis of Zika virus infection, subject to the terms of any authorization issued. To date, EUA has been issued for at least 15 Zika virus tests. Most of these approvals have been for nucleic acid tests (NATs) for the Zika virus RNA, with many of these tests employing the rRT-PCR method.
For each of the designated EUA Zika tests, the FDA issues a fact sheet for healthcare providers. The fact sheet (available on the website) contains the following information:
- Names the test kit or specific test approved by the FDA for EUA to detect Zika virus in human serum and/or urine with specified instruments. The FDA usually describes whether the EUA test is approved for detection of Zika virus RNA or IgM antibodies.
- Indicates that testing should be conducted only on specimens from individuals meeting the CDC's Zika clinical and epidemiological criteria for testing and should be performed by laboratories in the United States that are certified under the Clinical Laboratory Improvement Amendments (CLIA) of 1988 to perform high complexity tests, or by similarly qualified, non-US laboratories.
- Issues data submitted to the FDA by the kit manufacturer to justify the emergency use of the tests for detecting Zika virus and/or diagnosis of Zika virus infection.
- Gives a fact sheet typically related to (1) when the EUA test should be performed, (2) how specimens should be collected with appropriate infection control precautions and according to the manufacturer’s instructions, and (3) details on the interpretation and significance of a positive or negative test result.
For more details on EUA-issued diagnostic tests, refer to the following FDA link for a current list of assays and the associated letters of authorization, fact sheets, and product labeling:
