ZIKV Detect IgM Capture ELISA by InBios International, Inc: FDA Safety Communication - Wait for Confirmatory Test Results Before Making Patient Management Decisions.
The FDA is alerting physicians who care for pregnant women meeting CDC Zika virus clinical criteria and/or CDC Zika virus epidemiological criteria, that the U.S. commercial testing facility, Laboratory Corporation of America (LabCorp), has reported some false positive results from the ZIKV Detect test. Because confirmation tests may take a week to a month to complete, the FDA is issuing this alert so that health care providers and patients know about a higher likelihood of false positive results.
RECOMMENDATIONS: The FDA urges health care providers to be aware that:
- Positive IgM Zika virus results are only presumptive for the detection of antibodies to Zika virus.
- Confirmation of IgM Zika virus presumptive or possible positive results requires additional testing by CDC or by qualified laboratories.
- The confirmatory testing may take a week to a month to be performed, but can be prioritized if CDC is aware that the sample is from a pregnant woman. Laboratories should be notified of the patient’s pregnancy status.
Although the test is supposed to be used for "presumptive" diagnosis of Zika infection, which means there should be a confirmatory test, it would be quite interesting to know how it has been used in actual practice for the past 4 months, and how it is currently being used, even with the FDA warning. How many practitioners are aware of the warning? How many practitioners have or are recommending intervention (abortion?) based on a single result? How are pregnant women responding to a positive result for this test, given that they would have to wait up to a month for a confirmatory test?
And we all thought we were in the era of precision medicine?
© 2017 by Ralph Giorno MD