Orf, also known as ecthyma contagiosum or contagious pustular dermatitis, is a viral zoonotic disease resulting from the direct or indirect contact of damaged skin with infected animals. The causative microorganism is the orf virus, an epitheliotropic DNA virus from the Parapoxvirus group, which generally infects sheep, goats, and various other domestic and wild ovine animals. A male patient pr...

BACKGROUND Orf virus, the prototype of parapoxvirus, is the main causative agent of contagious ecthyma. Little is known about the status of the disease in Ethiopia and this study was aimed at determining its status using PCR as a confirmatory tool. METHODS a total of 400 randomly selected sheep and goat was screened for the identification of the virus using amplification of B2L gene and trans...

BACKGROUND Electron tomographic analysis can be combined with the simple and rapid negative staining technique used in electron microscopy based virus diagnosis. METHODS Standard negative staining of representative examples of parapoxviruses and paramyxoviruses was combined with electron tomographic analysis. RESULTS Digital sectioning of reconstructions of these viruses at a selected heigh...

Orf virus is the prototype parapoxvirus that causes the contagious skin disease orf. It encodes an orthologue of the cytokine interleukin (IL)-10. Recombinant orf viruses were constructed in which the viral interleukin-10 (vorfIL-10) was disabled (vorfIL-10ko) and reinserted (vorfrevIL-10) at the same locus and compared to wild-type virus for their ability to induce skin lesions in sheep. After...

Viruses have evolved numerous mechanisms to avoid host immune reactions. Here we report a mechanism by which Parapoxvirus ovis (PPVO) interferes with antigen presentation. PPVO (orf virus) causes orf, an acute skin disease of sheep and goats worldwide. Importantly, PPVO can repeatedly infect its host in spite of a vigorous inflammatory and host immune response to the infection. We demonstrate i...