Assessment of the Diagnostic Ability of the DIVA Real-Time PCR in a Duplex Configuration to Differentiate Between the Turkey Meningoencephalitis Vaccine and Wild-Type Viruses

Abstract

of the Diagnostic Ability of the DIVA Real-Time PCR in a Duplex Configu ration to Differentiate Between the Turkey Vaccine and Wild-Type Viruses. Abstract The avian flavivirus Turkey Meningoencephalitis Virus (ITV) causes a neuroparalytic disease of commercial turkeys, expressed in paresis, incoordination, dropping wings and mortality that is controlled by vaccination. The newly developed ITV real time RT-PCR Differentiating Infected from Vaccinated Animals assay, was further developed and transformed into a one-step duplex assay to distinguish between wild-type ITV strains and vaccine virus and to help identify in one amplification the virus type involved in the recent emergence of ITV in the summer-fall of 2017. The performance of the newly developed duplex DIVA assay was equal to that of the two monoplex assays in detecting clinical cases evaluated on the recent outbreak that affected most of the commercial turkey flocks of the age of ITV clinical affection. Using the ITV vaccine virus, we showed that the amplification parameters of the single-and duplex DIVA real-time PCR were similar. Next, the clinical cases were similarly amplified with the ITV-DIVA assay both as single-and duplex DIVA real-time PCR. In conclusion, a powerfully distinctive, sustainable and sensitive one-step duplex assay was put in action on the 2017 ITV outbreak.