Identification of equine herpesvirus 3 (equine coital exanthema virus), equine gammaherpesviruses 2 and 5, equine adenoviruses 1 and 2, equine arteritis virus and equine rhinitis A virus by polymerase chain reaction

Objective To develop rapid (<8 hour) tests using polymerase chain reaction (PCR) for the diagnosis of equine herpesvirus 3 (EHV3; equine coital exanth ema virus), equine gammaherpesviruses 2 (EHV2) and EHV5, equine adenovirus 1 (EAdV1), EAdV2, equine arteritis virus (EAV), equine rhinitis A virus (ER AV; formerly equine rhinovirus 1). Design Either single round or second round (seminested) PCRs were developed and validated. Methods Oligonucleotide primers were designed that were specific for each v irus, PCR conditions were defined and the specificity and sensitivity of th e assays were determined. The application of the tests was validated using a number of independent virus isolates for most of the viruses studied. The PCRs were applied directly to clinical samples where samples were availabl e. Results We developed a single round PCR for the diagnosis of EHV3, a semine sted PCR for EHV2 and single round PCRs for EHV5, EAdV1, EAdV2 and RT-PCRs for EAV and ERAV. The PCR primer sets for each virus were designed and show n to be highly specific (did not amplify any recognised non-target template ) and sensitive (detection of minimal amounts of virus) and, where multiple virus isolates were available all isolates were detected. Conclusion The development and validation of a comprehensive panel of PCR d iagnostic tests, predominantly for viruses causing equine respiratory disea se, that can be completed within 8 hours from receipt of clinical samples, provides a major advance in the rapid diagnosis or exclusion diagnosis of t hese endemic equine virus diseases in Australia.