Confirmatory diagnosis of contagious ecthyma (Orf) by polymerase chain reaction at Adet Sheep Research Sub-Center, Ethiopia: A case report

An outbreak of contagious ecthyma (CE) was investigated in June, 2012 with morbidity rate of 22% in Adet Sheep Research Sub-Center, Ethiopia. The results of this investigation indicated that the outbreak was caused by infection with CE virus. A polymerase chain reaction (PCR) assay for rapid diagnosis was applied to five scab samples obtained from sheep suspected for CE. To confirm whether the causative agent was present in skin scrapings, PCR of the complete B2L gene to diagnose CE was used in this study. The expected PCR fragments, approximately 1206 bp in length were obtained from DNA which had been extracted from tissue scrapings. All five skin scab samples were confirmed positive to CE by PCR. In conclusion, detailed phylogenetic analysis of CE virus is suggested in order to know the genetic origin of the virus strain as well as for the future choice for immunoprophylaxis.   Key words: Adet Sheep Research Sub-Center, B2L gene, contagious ecthyma, polymerase chain reaction (PCR), sheep.