Laboratory Corporation of America Holdings (LabCorp) announced the nationwide availability of testing for Zika virus using the Zika Immunoglobulin M (IgM) Antibody Capture Enzyme-Linked Immunosorbent Assay (Zika MAC-ELISA) developed by the Centers for Disease Control and Prevention (CDC).
The test received Emergency Use Authorization (EUA) from the US Food and Drug Administration (FDA), initially on February 26, 2016, and reissued on June 29, 2016, for the qualitative detection of Zika virus IgM antibodies in serum or cerebrospinal fluid (collected alongside a patient-matched serum specimen), and is being made available for the first time to commercial laboratories. It is intended to be used in the diagnosis of Zika virus infection in individuals meeting clinical and/or epidemiological criteria established by CDC for Zika virus infection risk.
"Zika virus continues to be a serious public health threat, and we are pleased to be among the first commercial laboratories to make the Zika MAC-ELISA test available to physicians for patients who meet CDC criteria for testing," said David P. King, LabCorp's chairman and chief executive officer. "This test enhances our offering in infectious diseases and can help to improve health and lives."
CDC clinical criteria for Zika virus infection testing include a history of clinical signs and symptoms associated with Zika virus infection. CDC epidemiological criteria for Zika virus infection testing include a recent history of 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 as part of a public health response.
Zika virus, which is primarily spread through Aedes aegypti mosquito bites and can also be spread through sexual contact without a barrier method, and from mother to fetus, has been identified in 1,658 individuals in the US as of July 27, 2016. All but one of those cases were associated with travel to areas with ongoing transmission of Zika virus or an epidemiological link with a person with such travel history (one was a laboratory exposure). More recently, officials have confirmed the first known cases in the continental United States of local mosquito-borne Zika virus transmission in Miami, Florida Public health officials have determined that Zika virus poses a potential public health emergency.
Most cases of Zika virus infection are relatively minor, and those infected may exhibit no symptoms or mild symptoms such as fever, joint pain, rash or redness of the eyes. However, Zika virus infection during pregnancy can cause birth defects, including fetal microcephaly, and may also contribute to other poor pregnancy outcomes, including stillbirth or miscarriage. Women who are exposed to Zika virus or diagnosed with Zika virus infection during pregnancy, or who become pregnant from a partner who has been exposed or diagnosed, should monitor their pregnancy closely with their healthcare provider.
The Zika MAC-ELISA testing is clinically appropriate for use in indicated persons during the period beginning soon after the onset of symptoms through approximately 12 weeks following infection and is intended for use in serum or cerebrospinal fluid when submitted with a patient-matched serum sample. By comparison, RT-PCR tests for Zika virus are clinically appropriate as a primary test only up to the first 7 to 14 days after the onset of symptoms, depending on the sample type tested. The RealStar Zika Virus RT-PCR Kit US, which is offered by LabCorp and is tested on urine paired with serum, is clinically appropriate up to the first 7 days following infection.
This test has not been FDA cleared or approved. This test has been authorized by FDA under an EUA for use by authorized laboratories and is only authorized for the duration of the declaration that circumstances exist justifying the EUA, unless the authorization is terminated or revoked sooner. It is authorized only for the detection of Zika virus infection and not for any other viruses or pathogens. As required by FDA, LabCorp will report all equivocal and presumptive positive results of this test to CDC and other public health authorities, as may be appropriate. LabCorp will also report to CDC any suspected occurrence of false negative results and significant deviations from the established performance characteristics of which it becomes aware.