Objectives :Equid herpes viruses 1 and 4 are the most important viruses affecting horses of all ages and other members of Equidae family (donkeys and mules) causing extensive economic losses from abortion , neonatal foal death and respiratory diseases. Infection caused by EHV-1,4 typically result in establishment of latent infection within the first weeks or months of life with subsequent viral reactivation causing clinical disease and viral shedding during periods of stress.
Methods :Three hundred sera sample were examined for the presence of specific antibodies against equine herpes virus 1 and 4 in horses , mules and donkeys from 6 governorates in Egypt by indirect ELISA test. Detection of EHV-1 and EHV-4 by nested multiplex PCR and sequence analysis .Isolation of EHV-1 on tissue culture (MDBK cells) and identification by indirect florescent antibody technique (IFAT).
Results : By ELISA test , 234 samples were found positive for the presence of EHV-1 and 4 antibodies. By PCR , one sample was found positive for EHV-1 and three samples for EHV-4. Sequence analysis of the amplified nested PCR products of representative EHV strains further confirmed the virus identity. In this work, we isolated EHV-1 on tissue culture(MDBK cells)from tissue samples including (liver, lung, kidney, spleen ,heart and brain of aborted fetuses ) collected from Arabian horses located in Cairo, Egypt . Sample was propagated for three passages on MDBK cells showing the CPE after 24 72 hours the characteristic grape like clusters of cells which are rounded and aggregated together in a separate manner and gradually increased till 70- 80% of the sheet was completely detached .Identification of positive EHV-1 isolate was done by indirect florescent antibody technique (IFAT) ; the result showed apple green fluorescent granules.
Conclusion: This work was planned to detect cause of many cases of abortion among horses in Egypt .The PCR technique proved to be more sensitive , rapid and efficient for diagnosis of EHV -1 &4 infection , while ELISA technique is more sensitive for detection of EHV-1 and 4 antibodies . This study will help in planning for vaccination against Egyptian isolates .
Key words: Arabian horses, Egypt, EHV-1 , EHV-4 , IFAT, nested multiplex PCR, ELISA.