Orf, a Human Parapoxvirus Infection.

Despite being common worldwide, parapoxvirus infections are regarded as neglected zoonoses because their incidence is either unknown or grossly overestimated. In ruminants all throughout the world, parapoxvirus produces oral lesions and infectious pustular dermatitis. The pathogen is typically spread directly via items contaminated with parapoxvirus and indirectly via a near contact with dermatological lesions that contain the virus on affected animals. Animals infected with the parapoxvirus typically exhibit no clinical symptoms, and the mode of parapoxvirus transmission is occasionally unclear. For accurate etiological diagnosis and appropriate therapy of patients affected by zoonotic infections, the significance of adopting a "One Health" approach and cross-sector collaboration between human and veterinary medicine should be emphasized. The causative pathogen of ecthyma contagiosum in general people is the orf virus, which mostly infects various animals, either pets or wildlife species. The illness primarily affects minute wild ruminants, sheep, cattle, deer, and goats, and it can spread to people through contact with infected animals or contaminated meats anywhere in the world. Taxonomically speaking, the virus belongs to the parapoxvirus genus. Thus pathogen can be detected from crusts for a very long period (several months to several years), and the virus is found to be resistant to inactivation with a hot or dry atmosphere. In immunocompetent individuals, the lesions often go away on their own with a period as long 2 months. Nevertheless, it necessitates the applying of diverse strategies, such as antiviral, immunological modulator, or modest surgical excisions in immunosuppressed patients. The interaction of the virus with various host populations aids in the development of a defense mechanism against the immune system. The parapoxvirus illness in humans is covered in this chapter. The orf illness, a significant known human parapoxvirus infection, is given specific attention.

A scalable downstream process for the purification of the cell culture-derived Orf virus for human or veterinary applications.

The large demand for safe and efficient viral vector-based vaccines and gene therapies against both inherited and acquired diseases accelerates the development of viral vectors. One outstanding example, the Orf virus, has a wide range of applications, a superior efficacy and an excellent safety profile combined with a reduced pathogenicity compared to other viral vectors. However, besides these favorable attributes, an efficient and scalable downstream process still needs to be developed. Recently, we screened potential chromatographic stationary phases for Orf virus purification. Based on these previous accomplishments, we developed a complete downstream process for the cell culture-derived Orf virus. The described process comprises a membrane-based clarification step, a nuclease treatment, steric exclusion chromatography, and a secondary chromatographic purification step using Capto® Core 700 resin. The applicability of this process to a variety of diverse Orf virus vectors was shown, testing two different genotypes. These studies render the possibility to apply the developed downstream scheme for both genotypes, and lead to overall virus yields of about 64 %, with step recoveries of >70 % for the clarification, and >90 % for the chromatography train. Protein concentrations of the final product are below the detection limits, and the final DNA concentration of about 1 ng per 1E + 06 infective virus units resembles a total DNA depletion of 96-98 %.

Development of a recombinase-aided amplification assay for detection of orf virus.

Orf, caused by orf virus (ORFV), is an important zoonotic disease that infects goat and sheep, leading to huge economic losses. ORFV can also cause cutaneous lesions in people who come in close contact with the diseased animals. Although accurate diagnostic methods for ORFV infection exist, there is a need for a rapid, specific, and sensitive method for easy clinical application. Here, we successfully established a recombinase-aided amplification (RAA) assay for rapid detection of ORFV. The analytical sensitivity of the assay for ORFV detection is 1 × 101 copies per reaction. Moreover, no cross-reaction was observed with other common DNA viruses. A total of 45 archived suspected ORFV infected nasal scab skin samples were examined by RAA and SYBR Green-based real-time polymerase chain reaction (PCR). Compared with the real-time PCR assay, the kappa values of the RAA assay for ORFV detection was 0.845 (p <0.001), indicating that both assay results were fully in agreement. In conclusion, this detection assay provides a rapid, sensitive, and specific method for ORFV detection and is suitable for ORFV clinical testing.

Human Infection with Orf Virus and Description of Its Whole Genome, France, 2017.

Zoonotic transmission of parapoxvirus from animals to humans has been reported; clinical manifestations are skin lesions on the fingers and hands after contact with infected animals. We report a human infection clinically suspected as being ecthyma contagiosum. The patient, a 65-year-old woman, had 3 nodules on her hands. She reported contact with a sheep during the Aïd-el-Fitr festival in France during 2017. We isolated the parapoxvirus orf virus from these nodules by using a nonconventional cell and sequenced the orf genome. We identified a novel orf virus genome and compared it with genomes of other orf viruses. More research is needed on the genus Parapoxvirus to understand worldwide distribution of and infection by orf virus, especially transmission between goats and sheep.

Feast of Sacrifice and Orf, Milan, Italy, 2015-2018.

Orf (ecthyma contagiosum) is an infection of the skin caused by a DNA virus belonging to the genus Parapoxvirus. We recently observed 7 cases of orf in Muslim men living in the metropolitan area of Milan, Italy, who acquired the infection after the Feast of Sacrifice.

Orf virus circulation in cattle in Turkey.

Orf virus (ORFV) causes contagious skin disease that mainly affects sheep and goats with zoonotic potential. However, there is not enough information about the association between ORFV and occurrence of skin disease in cattle. The present study describes outbreaks of ORFV infection in cattle in different provinces that are located in the Aegean, Central Anatolian and Mediterranean regions of Turkey. During the months of June and August 2017, vesicular fluid and scab samples were collected from cattle which had proliferative skin lesions. First, presence of lumpy skin disease virus (LSDV) and bovine herpesvirus 2 (BoHV-2, known as the causative agent of pseudo-lumpy skin disease) were investigated by real time PCR and PCR, respectively. Then, samples tested for the presence of parapoxviruses by PCR using primers specific to major envelope protein gene (B2L). Parapoxvirus DNA was detected in investigated samples whereas LSDV and BoHV-2 DNA were not detected. The analysis of the B2L gene sequences revealed that cattle were infected with ORFV. The isolates in the present study shared 100% sequence identity at the nucleotide and amino acid level when compared with previously characterised Turkish field ORFV isolates from goats in 2016. Results of the study show unusual infection of cattle with ORFV, and suggest that ORFV jumps the host species barrier from goats to cattle.

Nódulo eritematoso en un niño / Erythematous nodule in a child

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Genomic characterization of two Orf virus isolates from Jilin province in China.

Orf virus (ORFV), a typical member of the Parapoxvirus genus within the family Poxviridae, which is the causative agent of Orf, a common epitheliotropic viral disease of sheep, goats, wild ruminants, and humans. In the present study, we sequenced the complete genomic sequences of two ORFV strains (ORFV-SY17, isolated from sheep, and ORFV-NA17, isolated from goat) and conducted the comparative analysis of multiple ORFVs. The complete genomic sequence of ORFV-SY17 was at length of 140,413 bp, including 131 potential open reading frames (ORFs) flanked by inverted terminal repeats (ITRs) of 4267 bp at both ends. The ORFV-NA17 strain displayed the similar genome structure with ORFV-SY17. The whole genomic sequence of ORFV-NA17 strain was 139,287 bp in length and contained 132 ORFs flanked by ITRs of 3974 bp. The overall G+C contents of ORFV-SY17 and ORFV-NA17 genome sequences were about 63.8% and 63.7%, respectively. The ITR sequences analysis showed that ORFV-SY17 and ORFV-NA17 contained the terminal BamHI sites and conserved telomere resolution sequences at both ends of their genome. In addition, comparative analysis of ORFs among ORFV-SY17, ORFV-NA17, and other ORFV strains revealed several sequence variations caused by insertions or deletions, especially in ORFs 005 and 116, which were very likely associated with host species. Phylogenetic analysis based on the complete genome sequences revealed that ORFV-SY17 was genetically closely related to NA1/11 and HN3/12 strains derived from sheep, while ORFV-NA17 was closely related to YX strain derived from goat. The multiple alignment of deduced amino acid sequences further revealed the genetic relationship between host species and genetic variations of ORFV strains. Taken together, the availability of genomic sequences of ORFV-SY17 and ORFV-NA17 strains from Jilin Province will aid in our understanding of the genetic diversity and evolution of ORFV strains in this region and can assist in distinguishing between ORFV strains that originate in sheep and goats.

Poxviral E3L ortholog (Viral Interferon resistance gene) of orf viruses of sheep and goats indicates species-specific clustering with heterogeneity among parapoxviruses.

Orf is a contagious disease posing a serious threat to animal and human health. E3L is one of the evolutionarily acquired immunomodulatory proteins present in orf virus (ORFV) and is responsible for conferring resistance to interferons among poxviruses. Genetic analysis of ORFV isolates of different geographical regions including Indian subcontinent targeting viral interferon resistance (VIR) gene (a homolog of vaccinia virus E3L gene) revealed a high percentage of identity among themselves and other ORFV isolates at both nt and aa levels as compared to low identity among parapoxviruses (PPVs). Phylogenetic analysis showed species-specific clustering among PPVs along with sub-clusters based on host species of origin among ORFVs infecting sheep and goats. Conserved amino acids in N-terminal Z-DNA binding domain and C-terminal ds RNA binding domain of VIR proteins of PPVs corresponding to ORFV VIR positions namely N37, Y41, P57, and W59 (necessary for Z-DNA binding) and E116, F127, F141, and K160 (necessary for dsRNA binding) were found. Further, the predicted protein characteristics and homology model of VIR protein of ORFV showed high structural conservation among poxviruses. This study on E3L genetic analysis of ORFV isolates may provide a better understanding of the molecular epidemiology of circulating strains in India and neighboring countries. Also, E3L deleted or mutated ORFV may be an as vaccine candidate and/or compounds blocking E3L may prove as an effective method for treating broad spectrum poxviral infections, suggesting a wider application in control of poxvirus infections.

Identification and characterization of Orf viruses isolated from sheep and goats in Southern Italy.

Orf virus (ORFV; Family: Poxviridae) is the causative agent of contagious ecthyma, or Orf disease in sheep, goats and other domestic or wild ruminants with a worldwide distribution. The disease is endemic in Italy, but few data are available about its distribution and epidemiology. In the present study we analysed 32 clinical samples, obtained from crusted scab lesions of 5 goats and 27 sheep, from 19 suspected outbreaks of contagious ecthyma in Apulia and Basilicata regions between 2012 and 2014. Negative staining electron microscopy (EM) and polymerase chain reaction (PCR) targeting the late transcription factor gene (VLTF-1) were used to identify the virus. Isolation was also attempted on BHK-21 cell line. PCR was proved to be more sensitive than EM, as it detected the virus in 28 out of 32 samples, whereas the EM detected it only in 26 out of the 32 samples. The majority of isolated strains forms a monophyletic group; these isolates, according to the VLTF-1 sequencing,  are high related to ORFV strains previously shown to circulate in Southern Italy.

Erythema multiforme after orf virus infection.

The case of a 6-year-old boy with multiple, target-shaped lesions and a crusted nodule on his right index finger is presented. Based on clinical findings and the patient's recent contact with sheep and goats, a diagnosis of orf disease associated with erythema multiforme was suspected. Microscopy studies confirmed the presence of parapoxvirus in the primary lesion. Orf-induced erythema multiforme is a rare complication of orf in children, possibly related to the presence of orf virus DNA in erythema multiforme lesions.

Pathogenicity of blood orf virus isolates in the development of dairy goat contagious pustular dermatitis.

Contagious pustular dermatitis is an exanthematous zoonotic disease caused by the orf virus. Pandemic outbreaks of this disease cause great economic losses, while the pathogenesis of this disease still remains obscure. In this study, blood samples were collected from 628 asymptomatic goats across China for PCR-based virus detection. We detected the orf virus in the blood of asymptomatic goats. Moreover, the orf virus obtained from the blood of infected goats was infectious and induced typical symptoms of contagious pustular dermatitis after inoculation of uninfected dairy goats. In summary, our data provide evidence that asymptomatic animals may be carriers of orf virus. Our findings should contribute to elucidating the details underlying the pathogenesis of contagious pustular dermatitis.

Poxvirus-Induced Vascular Angiogenesis Mimicking Pyogenic Granuloma.

The orf virus, a member of poxvirus family, is a zoonotic parapoxvirus endemic in many countries, mostly seen among sheep, goats, oxen, and may be transmitted to humans. Orf virus infections may induce ulceration, papulonodular, pustular, or ecthyma lesions in the skin. Rarely, orf virus provokes extensive vasculoendothelial proliferation by encoding an apparent homolog of the mammalian vascular endothelial growth factor family of molecules. The vascular endothelial growth factor-like viral gene product is expressed early during infection and could be responsible for the induction of endothelial proliferation. Here, a 6-year-old male patient with poxvirus-induced widespread vascular angiogenesis is presented, which developed ten days after a thermal burn.

Comparative sequence and structural analysis of Indian orf viruses based on major envelope immuno-dominant protein (F1L), an homologue of pox viral p35/H3 protein.

Orf virus (ORFV), a member of the genus Parapoxvirus in the family Poxviridae, is the cause of orf, a highly contagious zoonotic viral disease that affects mainly sheep and goats. In the present study, the sequence and phylogenetic analysis of Indian ORFV isolates (n = 15) from natural outbreaks in sheep and goats belonging to different geographical regions were analysed on the basis of F1L gene along with homology modelling of F1L protein. Multiple sequence alignments revealed highly conserved C-terminus and heterogeneity of N-terminus region of F1L among all orf viruses studied. Further, a comparative sequence alignment indicated conservation of various motifs such as glycosaminoglycan (GAG), Asp/Glu-any residue-Asp (D/ExD) and a Cx3C chemokine like motif among all poxviruses and unique motifs (proline rich region [PRR] and Lys-Gly-Asp [KGD]), in parapoxviruses including ORFV isolates irrespective of geography and host species. Phylogenetically, two major clusters were noticed which included Indian orf isolates along with foreign isolates. Structurally, ORFV F1L resembled the topology as exhibited by its homologue vaccinia virus H3 protein with mixed ß/α folds and ligand binding specificity in docking models. We noted that despite differences in host cell specificity and pathogencity, poxvirus proteins especially ORFV F1L protein and its homologues presumed to share similarities as they are highly conserved irrespective of species and countries of origin. Further, the study also indicated the possibilities of differentiation of ORFV strains based on N-terminal heterogeneity despite highly conserved C-terminal region with conserved motifs.

Molecular identification and investigations of contagious ecthyma (Orf virus) in small ruminants, North west Ethiopia.

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 transfection of mammalian cells (VERO cells). RESULTS: Out of 400 animals screened for infection of the virus, 48 animals were found positive to PCR and revealed an overall incidence of 12%. Different epidemiological parameters were considered to look at the association with incidence of the disease and of which, only species of the animal(sheep), non-vaccinated and non-treated animals, nursing animals, poor body condition animals, extensively managed animals, animals having mouth lesion, and study areas having outbreak history showed higher prevalence. A univariate logistic regression analysis showed statistically significant difference in all variables (P < 0.05). Whereas, age and sex of animals showed no significant difference (P < 0.05). CONCLUSION: The result of the present finding showed high incidence of Orf virus in the region as confirmed through PCR.

Genetic diversity of Orf virus isolated from sheep in Uruguay.

Orf virus (ORFV) is the etiological agent of contagious ecthyma, a disease widely spread in the world that occasionally causes zoonotic infections. This work is the first molecular characterization of ORFV in Uruguay, where we analyzed twenty-one sheep samples, eighteen of which were recovered from thirteen ORFV outbreaks that occurred during 2004 to 2011 as well as three strains from a national vaccine. Phylogenetic analysis and the derived amino acid sequences from the B2L gene suggest that the Uruguayan virus do not form a unique cluster, with most of them displaying similarities with worldwide ORFV isolates as well as our vaccine strains.