A Duplex Fluorescent Microsphere Immunoassay for Detection of Bluetongue and Epizootic Hemorrhagic Disease Virus Antibodies in Cattle Sera

Abstract

Bluetongue virus (BTV) causes internationally reportable hemorrhagic disease in cattle, sheep, and white-tailed deer. The closely related, and often co-circulating, epizootic hemorrhagic disease virus causes a clinically similar devastating disease in white-tailed deer, with increasing levels of disease in cattle in the past 10 years. Transmitted by Culicoides biting midges, together, they constitute constant disease threats to the livelihood of livestock owners. In cattle, serious economic impacts result from decreased animal production, but most significantly from trade regulations. For effective disease surveillance and accurate trade regulation implementation, rapid, sensitive assays that can detect exposure of cattle to BTV and/or EHDV are needed. We describe the development and validation of a duplex fluorescent microsphere immunoassay (FMIA) to simultaneously detect and differentiate antibodies to BTV and EHDV in a single bovine serum sample. Performance of the duplex FMIA for detection and differentiation of BTV and EHDV serogroup antibodies was comparable, with higher sensitivity than commercially available single-plex competitive enzyme-linked immunosorbent assays (cELISA) for detection of each virus antibody separately. The FMIA adds to the currently available diagnostic tools for hemorrhagic orbiviral diseases in cattle as a sensitive, specific assay, with the benefits of serogroup differentiation in a single serum sample, and multiplexing flexibility in a high-throughput platform.

Perspectives on the Changing Landscape of Epizootic Hemorrhagic Disease Virus Control

“…A c-ELISA to detect BTV IgM antibodies was also tested for cross-reactivity with EHDV, and was found to detect EHDV-6 IgM antibodies in a portion of sera from cattle experimentally infected with EHDV-6 [93]; this suggests that there are diagnostic tools with the potential to detect antibodies specific for the acute phase of EHDV infections. Most recently, a fluorescent microsphere immunoassay (FMIA) using whole-virus antigen preparations was developed with the capability of differentiating bovine antibodies to BTV and EHDV in a single, small volume serum sample [94].…”