Rapid methods for detection of Equine Herpes Virus 1 in Arabian Horses in Egypt

Abstract

Equid herpesvirus 1 (EHV-1) is the most common virus causing pathological disorders in horses and is a major agent of large-scale abortion outbreak, which was identified in mares as sporadic or epidemic cases usually during the last trimester of pregnancy. As EHV1 is a very contagious disease that can occur as an explosive outbreak of abortion or neurological signs with high mortality, quick and innovative techniques of diagnosis are important. In Egypt, EHV-1 has a significant threat to the equine industry and a major concern and challenge to the equine veterinary and scientific community because of its effect on animal welfare and performance. In this study, 66 samples were collected over 3 years from Clinical cases. All samples were collected from Arabian horse studs located in Cairo and Giza. EHV-1 was detected molecularly in twenty-five horses with different clinical forms such as; respiratory disorder, abortion, stillbirth, early neonatal death, and myeloencephalopathy. Molecular diagnosis was carried out using and real time PCR and nested PCR targeting the EHV-1 gB gene. After partial sequencing of the glycoprotein B (gB) gene of Egyptian EHV-1 field strains isolated from these clinical cases, it was shown that genetically identical EHV-1 strains were still circulating in Egypt during different years and, these strains were closely related to the European EHV-1 strains. Furthermore, EHV-1 isolated in the present study and to EHV-1 strains published previously in the GenBank database was shown very little differences for the amino acid sequences. This molecular report would be valuable for monitoring EHV-1 infection in Egypt and determining the gB gene sequence of newly identified EHV-1 field strains which is the most conserved region in virus DNA and frequently used as a target for diagnostic PCR protocols for future outbreaks.