Thesis (Ph.D.) - Cairo University - Faculty of Veterinary Medicine - Department of Internal Medicine and Infectious Diseases

Studying the prevalence of Equine herpes virus-1( EHV-1), Equine herpes virus- 4(EHV-4) and Equine Viral Arthritis (EVA) infection among equines in different governorates of Egypt. Evaluating the indirect Enzyme-Linked Immuno-Sorbent Assay (ELISA) for the diagnosis of them in comparison with the virus isolation. Assessing the efficacy of Polymerase Chain Reaction (PCR) for the diagnosis of the viral infection by using the horses nasopharyngeal swabs isolated virus and the aborted foeti tissues. One hundred eighty two equines of different ages, sexes, localities and breeds showing signs of fever, respiratory manifestations, abortions, ataxia, hind limb paralysis, limb edema, foal depression and death; were examined. The viral isolation on both histopathology and Baby Hamster Kidney (BHK) cell culture, the aborted foeti were histologically examined for the detection of inclusion bodies, the serum samples were collected to detect Immunoglobulin-G specific to EHV-1,EHV-4 and EVA by using ELISA, EHV-4 and EVA were negative .the horses nasopharyngeal swabs isolated virus and the aborted foeti tissues were tested by PCR using specific primers to EHV-1 to confirm the infection with EHV-1.The prevalence of EHV-1 infection in the examined animals were recorded as 4.94%. it was prevalent in Cairo, Giza, Kafr Elsheikh, Monofeia, El Sharkia governorates. The EHV-1 was isolated on the embryonated chicken eggs and the pock lesion was appeared on the chorio-allantoic membranes. The cytopathic effects were also observed on the tissue culture. The Liver of aborted foeti showing necrosis of all hepatic tissue and activation of kuffer cells with heamosidren and the detection of esinophilic Intranuclear inclusion bodies. Indirect ELISA could detect IgG in all infected equines(N=9) from which EHV-1 isolated. PCR proved the infection with EHV-1 in the aborted foeti (N=3) tissues and gave the similar results by using the horses nasopharyngeal swabs isolated virus where 489 bp PCR products were detected in both. EHV-1 is prevalent in Egypt in different governourates. EHV-1 infection could diagnosed by intranuclear esinophilic inclusion bodies in the aborted foeti tissues. The indirect ELISA could diagnose EHV-1 infection in all ages and sexes groups. PCR on aborted foeti tissues is better for the diagnosis of EHV-1 infection than that on the horses nasopharyngeal swabs isolated virus because it save time and money. the study indicated that there are no EHV-4 and EVA infection found in Egypt

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