TDK conference 2016

The Equid herpesvirus 5 (EHV-5) belongs to the Gammaherpesvirinae subfamily within the Percavirus genus. The EHV-5 is among those viruses that can naturally infect the equids. Many viruses in Herpesviridae family cause severe diseases that are spread worldwide. Despite this fact, the exact range and pathogenic role of EHV-5 is still undefined. The first isolation of the virus was in 1970 Australia, from two quarantined horses showing respiratory tract signs. Since then EHV-5 has been detected from all over the world in healthy and affected horses as well, but predominantly in the last 20 years. Based on these studies there is increasing evidence of the connection between EHV-5 infection and the development of a newly described disease, the equine multinodulary pulmonary fibrosis (EMPF). The aim of our study was to get an insight into the prevalence of the virus in a closed herd of Przewalski wild horses, living in Hortobágy steppe, through investigation samples from those animals that were eliminated from the herd because of different health problems. We examined samples from 11 horses; we had 11 nasal swabs, 9 blood samples and 10 lung samples. We have investigated the presence of EHV-5 nucleic acid by polymerase chain reaction (PCR), using virus specific primers. During the study 6 (54,5%) out of 11 samples were found to be positive for EHV-5 infection, in 2 (18,2%) animals in all 3 samples could the virus be found; in 1 (9,9%) case only 2 samples were positive and in 3 (33,3%) cases only 1 sample contained the virus. In 5 out of the 6 positive animals interstitial pneumonia could be seen and among them 1 had solitary nodular fibrosis and in another one multifocal fibrosis. According to the results, the EHV-5 is relatively widespread in the herd of Przewalski horses in Hortobágy. However, presumably further factors are needed beside EHV-5 infection to evolve EMPF.