PSVII-37 First molecular detection of Equine Herpesvirus type 2 (EHV-2) and type 5 (EHV-5) in upper respiratory liquids of healthy training horses from southern Brazil

Multiple pathogens may cause and sustain respiratory infection in horses, either alone or as co-infection, leading to disruption and interruption of training, racing and other competitions. Molecular approaches have successfully provided opportunity for pathogen involvement and characterization, particularly from samples of horse upper respiratory tract. Accordingly, the aim of this study was to molecularly assess bronchoalveolar lavage fluid (BALF) samples from 10 healthy training horses at the Jockey Club of Parana State, southern Brazil. Virus-specific real-time polymerase chain reaction (qPCR) assays were applied as panel for concomitant detection of Equine Adenovirus, Equine Influenza Virus, Equine Herpesvirus Type 1 (EHV-1), Type 2 (EHV-2), Type 4 (EHV-4), and Type 5 (EHV-5), Equine Rhinitis A Virus, Equine Rhinitis B Virus, and Streptococcus equi subsp. equi. Amplicons from positive samples were amplified and sequenced to confirm the virus identification. Results have confirmed the first molecular detection of EHV-2 and EHV-5 in healthy training horses of Brazil, with an overall 3/10 (30%) EHV positivity. Two horses were positive for at least one EHV, and one was positive for both EHV-2 and EHV-5. No horse presented clinical signs of respiratory disease at the time or following samplings. These findings may provide new insights on the epidemiological situation of EHV-2 and EHV-5 in Brazil, highlighting the importance of molecular detection and active surveillance in clinically healthy horses, which may act as spreading infection source for younger equines.