End-Point RT-PCR Assays for Detection and Typing of Epizootic Hemorrhagic Disease Virus

The emergence of EHDV in Europe during the autumn of 2022 reinforces the need for molecular tools (RT-PCR) for rapid detection of animals infected with this virus. Viral genome testing can be performed on whole blood under anticoagulant, spleen, and bloody organ homogenates from ruminants. It can also be performed on cell culture following viral isolation tests. Various so-called classical or end-point RT-PCRs will be described, which permit the amplification of a part of the viral genome (targeting segment 7) allowing the detection of EHDV whatever the serotype (pan-RT-PCR) and also to amplify a portion of the gene coding the viral protein (VP) 2 enabling serotyping. The PCR amplification products are visualized by agarose gel electrophoresis. Sequencing of the type-specific RT-PCR amplification products allows for the serotype of the virus to be determined.