Quest Diagnostics has received an emergency use authorization (EUA) from the FDA for the Zika Virus RNA Qualitative Real-Time RT-PCR (Zika RT-PCR) test. The proprietary molecular test is intended for the qualitative detection of RNA from the Zika virus in human serum specimens from certain individuals.
The test is the first from a commercial laboratory provider to be granted an EUA for testing patients for Zika virus RNA. Until now, the only Zika tests authorized by the FDA under an EUA were available from the Centers for Disease Control and Prevention (CDC) and were used only in qualified laboratories designated by the CDC. Quest Diagnostics plans to make the new test broadly available to physicians for patient testing, including in Puerto Rico, early in the week of May 2.
The FDA’s EUA authorizes qualified laboratories designated by Focus Diagnostics, Inc. (a Quest subsidiary), and, in the United States, certified under the Clinical Laboratory Improvement Amendments of 1988 (CLIA) to conduct high-complexity tests, to perform the Zika RT-PCR test. The test can potentially be performed at any CLIA high-complexity laboratory in the Quest Diagnostics network, which includes several dozen labs in the U.S., including in Toa Baja, Puerto Rico. For now, only the company’s Focus Diagnostics reference laboratory in San Juan Capistrano, California, which developed and validated the new test, will perform it.
The real-time RT-PCR test is intended only for the qualitative detection of RNA from the Zika virus in human serum specimens from patients meeting CDC clinical criteria for Zika virus infection (e.g., clinical signs and symptoms associated with the disease) and/or CDC Zika virus epidemiologic criteria (e.g., a history of residence in or travel to a geographic region with active Zika virus transmission at the time of travel, or other epidemiologic criteria for which Zika virus testing may be indicated).
The Zika RT-PCR test has not been FDA approved. It has been authorized for use by the FDA under an EUA and is authorized only for the duration of the declaration. In the U.S., positive results of this test must be reported to the CDC. The diagnosis of Zika virus infection must be made based on the patient’s history, signs, symptoms, exposure likelihood, and other laboratory evidence in addition to the identification of Zika virus DNA. Negative results do not preclude Zika virus infection and should not be used as the sole basis for patient management decisions.
International and U.S. health officials have confirmed that Zika virus infection during pregnancy can cause fetal microcephaly and other birth defects, and they have warned that local outbreaks in the U.S. are possible. Symptoms of Zika infection include fever, rash, joint pain, and conjunctivitis. The CDC recommends RT-PCR testing during approximately the first seven days of symptom onset for certain patients. A negative result does not preclude infection, and additional serological testing to evaluate the body’s immune response to infection should be considered within two to 12 weeks after symptom onset.
The CDC also recommends testing for individuals with symptoms suggestive of Zika virus infection who have traveled within the last two weeks to an area with ongoing virus transmission; for asymptomatic pregnant women with a history of residence in or travel to areas of active Zika infection; for asymptomatic pregnant women whose male sexual partners have traveled to or lived in an area of active Zika infection; and for infants born to mothers who live or traveled to areas with Zika virus transmission during their pregnancy, including both molecular and serologic testing of infants who are being evaluated for evidence of a congenital Zika virus infection.
Quest Diagnostics plans to offer serologic test services assuming FDA authorization of serological test kits for emergency use.
Source: Quest Diagnostics; April 28, 2016.