Orf virus infecting sheep and goats belongs to genus Parapoxvirus, subfamily
Chordopoxvirinae, family Poxviridae. It causes contagious pustular dermatitis in sheep and
goats worldwide, including Egypt. This work aimed for molecular and serological diagnosis
of Orf virus in infected sheep and goats during summer season 2020. Ten samples of skin
lesions from suspected sheep and goats from different areas of Minufiya governorate
including Queisna, Tala, and Ashmoon were subjected to direct detection using PCR primers
targeting ORF 045 gene which encodes the late transcription factor (VLTF-1). Positive
samples on PCR detection were isolated on Specific Pathogen Free- Embryonated Chicken
Eggs (SPF-ECEs) then viral antigen was detected using indirect-fluorescent antibody
technique (IFAT) and molecular detection of viral DNA using PCR. Positive results were
shown in 7 samples (5/7 of sheep samples and 2/3 of goat samples) using PCR. Virus
isolation from positive samples on SPF-ECE that gave positive results by the 3rd passage in 5
of 7 samples (3 sheep isolates and two goat isolates). Signs of inoculated viral samples on
CAM of SPF-ECEs showed thickening, edema, and hemorrhage of the membrane. These
isolates showed positive results upon identification using IFAT and PCR. It was concluded
that Orf virus was circulating among sheep and goats in Minufiya governorate Egypt, during
summer 2020.