Zika virus (ZIKV) is a mosquito-borne, single-stranded, positive-sense RNA virus belonging to the Flaviviridae family. It is closely related to other members of the Flavivirus genus including dengue virus, West Nile virus, yellow fever virus, tick-borne encephalitis virus, and Japanese encephalitis virus. ZIKV was first isolated from a rhesus monkey in Uganda in 1947 and the first human cases were detected in the 1950s in Uganda, Tanzania, and Nigeria. Since that time, there have been significant outbreaks in Africa, Southeast Asia, and the Pacific Islands, but the majority of the cases appeared to cause only mild illness. It wasn’t until the outbreak in Brazil in 2015 and the rapid spread of ZIKV across Latin America and the Caribbean that it was declared a public health emergency of international concern by the World Health Organization in February 2016. This declaration was due to a dramatic increase in the number of reported cases of prenatal microcephaly and adult neurological disorders such as Guillain-Barré syndrome in Brazil and other ZIKV affected areas.
The potential association of ZIKV with these severe neurological problems highlights the need for accurate testing. Current methods of early detection of the virus include various real-time and conventional RT-PCR tests to identify viral RNA in the serum or detection of the Zika virus NS1 protein by ELISA. While these tests have the potential to be highly sensitive and specific, there is a limited time window for sample collection as the presence of the virus in the blood typically peaks during the first five days of symptoms. In addition to these, serological tests have been developed to detect the immune response against the virus including ZIKV IgM and IgG ELISAs. Anti-ZIKV IgM and IgG antibodies typically appear four to ten days following the onset of symptoms and can persist for months, allowing a significantly longer time window for sample collection. The limitation of these assays, however, is the potential for cross-reactivity with antibodies directed against other flaviviruses, particularly in cases where there is a previous history of flavivirus infection or vaccination.
On September 19, 2017 at 11:00 am CST, Christian Erickson, a member of the Bioassay Development group at R&D Systems will present a webinar describing the development of a new serological Anti-Zika Virus IgG ELISA that displays minimal dengue virus cross-reactivity, along with the key advantages and disadvantages of the current methods being used for ZIKV detection. Our panel of experts will be on hand to answer questions about how the assay works and how it was tested. Key topics include:
For a preview of these topics, see our recent scientific poster, A New Immunoassay for Detecting Anti-Zika Virus IgG with Very Low Dengue Virus Cross-Reactivity. Registration for the webinar will provide access to the live webinar and on-demand access to view the recorded webinar following the event.