Zika IgG assay
Roche has launched the first fully automated Zika IgG immunoassay, the Elecsys Zika IgG immunoassay for CE Mark countries, to help detect Zika virus infection. Accurate diagnosis of an infection with Zika virus is an urgent medical need, particularly for pregnant women, as an infection with Zika virus can cause impaired neurological development in babies whose mothers were infected during pregnancy. Diagnostic testing enables healthcare professionals to assess the immune status of patients, which can be of particular importance to expectant mothers, their partners and travellers, and detect evidence of a recent Zika virus infection.
This new serological assay complements a significant advancement from Roche for Zika virus screening. On 5 October 2017, the U.S. Food and Drug Administration (FDA) granted IVD status to the cobas Zika test, for use with the cobas 6800/8800 systems, for the screening of blood and plasma donations in the United States.
Zika virus serological testing could be used for accurate diagnosis of Zika virus infection when the virus’ RNA is no longer detectable in the patient’s blood sample. Due to the similarity of Zika virus to other viruses, such as Dengue virus, the Elecsys Zika IgG assay was developed as a highly specific assay to limit cross-reaction and reduce the occurrence of false positive results. This assay can also be used to later determine the seroprevalence of Zika virus in different populations and countries at risk to assess the level of immune status in a country.
Zika virus belongs to the Flaviviridae family of viruses, including Dengue, Yellow Fever, Japanese encephalitis and West Nile viruses. Zika virus is mainly spread by infected mosquitoes, though transmission may also occur through mother-to-child, sexual intercourse and infected donor blood used for transfusions. There is now evidence that Zika virus is linked to birth defects in fetuses and newborns, and neurological complications in adults. Based on a systematic review of the scientific literature, in 2016 the World Health Organization (WHO) concluded that Zika virus infection during pregnancy may cause congenital brain abnormalities, including microcephaly; and that the virus is a trigger of Guillain-Barré syndrome and subsequently declared Zika virus as a public health emergency. Today, Zika virus infection remains a significant enduring public health challenge, requiring intense action, but is no longer classified as a public health emergency.