Diagnosis of Zika virus infection on a nanotechnology platform

Antibody-based diagnosis of Zika virus (ZIKV) infection is complicated by cross-reactivity with antibodies against dengue virus. Hongjie Dai and colleagues report their development of a new IgA- and IgG-based diagnostic test that detects ZIKV with high specificity. We developed a multiplexed assay on a plasmonic-gold platform for measuring IgG and IgA antibodies and IgG avidity against both Zika virus (ZIKV) and dengue virus (DENV) infections. In contrast to IgM cross-reactivity, IgG and IgA antibodies against ZIKV nonstructural protein 1 (NS1) antigen were specific to ZIKV infection, and IgG avidity revealed recent ZIKV infection and past DENV-2 infection in patients in dengue-endemic regions. This assay could enable specific diagnosis of ZIKV infection over other flaviviral infections.