Use of a local anaesthetic and antiseptic wound formulation for the treatment of lambs naturally infected with Orf virus.

Contagious ecthyma (CE) is a worldwide highly contagious zoonotic viral skin disease of sheep and goats. Treatment for Orf virus (ORFV) infection usually involves topical and oral antibiotics. An anaesthetic and antiseptic topical gel (Multisolfen® or Tri-Solfen®; MS®, Medical Ethics, Australia) has been documented as an efficacious therapy for lesions from mucosal and epithelial viral infections in ruminants. The present study tested a new treatment protocol of MS® for CE therapy on-farm in 150 lambs naturally infected with ORFV. Lambs were divided into three cohorts of 50 lambs each (C, D and E). Cohort C was treated with MS® 3 times with an interval of 3 days between treatments, cohort D was treated daily with hypochlorous acid, whilst cohort E served as untreated controls. The lambs were examined clinically every two days, weight measured weekly, with whole blood and sterile swabs from ORFV lesions collected for haematological analysis and specific ORFV PCR. Cohort C presented fewer lambs displaying ORFV-associated lesions than other cohorts at different times of the experiment. Further, lesions treated with MS® were milder compared with other cohorts. However, following cessation of therapy, most of the lambs again developed ORFV-associated lesions. No differences between cohorts were observed in weight, haematological and PCR results. These findings suggest that topical treatment with MS® is effective for CE in field conditions, especially in the first stages of the clinical course, although treatment with MS® may need to be extended a minimum of 4 weeks.

Finger nodules with a papulovesicular hands and feet eruption: a complicated human Orf virus infection.

BACKGROUND: Orf virus (ORFV) is the pathogen responsible for Orf, a zoonotic viral infection that can be spread to humans from sheep and goats. Here, we present a case of human Orf complicated by an immune-related reaction, to raise awareness of this under-recognized disease avoiding unnecessary investigations and overtreatment. CASE REPORT: A 51-year-old woman with no previous medical history presented with a one-week history of three asymptomatic swelling nodules with a grey necrotic center and red outer halo on her index finger. At physical examination there was also a pruritic papulovesicular eruption on her hands and feet. She reported a recent contact with a goat which had a similar nodular lesion in its mouth. A biopsy of the lesions was performed and a diagnosis of Orf complicated by widespread erythema multiforme was made based on the clinical and histopathological features. The lesions spontaneously resolved within the next 2 weeks. CONCLUSIONS: Orf is not very prevalent in our region, so we performed a biopsy of the lesion to guide us toward a diagnosis. However, we should remember that the diagnosis of ecthyma relies on clinical evaluation and epidemiological criteria.

Contagious ecthyma in Egypt: Clinical, virological and molecular explorations.

Contagious Ecthyma (CE) is a highly contagious viral disease of sheep and goats with worldwide distribution. The present study aimed to provide a clinical description of contagious ecthyma in four sheep flocks and screen the possible genetic variation in the B2L gene of the detected isolates. Oral lesions were collected and inoculated into chorioallantoic membrane (CAM) of 11 days embryonated chicken eggs. Polymerase chain reaction and direct sequencing of the B2L gene was conducted. Infected sheep exhibited anorexia with a development of nodular lesions evolving in proliferative thick scabs around oral commissures. The inoculated CAM showed small-sized white pock lesions accompanied with thickening of CAM. The partial length of B2L gene (592 bp) was successfully amplified in samples collected from four flocks. The isolated strains belong to genotype I/I and I/II. Sequence and evolutionary analysis illustrate that B2L gene (ORF011) are highly conserved among Orf viruses isolated from different countries.

Deletion of gene OV132 attenuates Orf virus more effectively than gene OV112.

Orf virus (ORFV), a Parapoxvirus in Poxviridae, infects sheep and goats resulting in contagious pustular dermatitis. ORFV is regarded as a promising viral vector candidate for vaccine development and oncolytic virotherapy. Owing to their potential clinical application, safety concerns have become increasingly important. Deletion of either the OV132 (encoding vascular endothelial growth factor, VEGF) or OV112 (encoding the chemokine binding protein, CBP) genes reduced ORFV infectivity, which has been independently demonstrated in the NZ2 and NZ7 strains, respectively. This study revealed that the VEGF and CBP gene sequences of the local strain (TW/Hoping) shared a similarity of 47.01% with NZ2 and 90.56% with NZ7. Due to the high sequence divergence of these two immunoregulatory genes among orf viral strains, their contribution to the pathogenicity of Taiwanese ORFV isolates was comparatively characterized. Initially, two ORFV recombinants were generated, in which either the VEGF or CBP gene was deleted and replaced with the reporter gene EGFP. In vitro assays indicated that both the VEGF-deletion mutant ORFV-VEGFΔ-EGFP and the CBP deletion mutant ORFV-CBPΔ-EGFP were attenuated in cells. In particular, ORFV-VEGFΔ-EGFP significantly reduced plaque size and virus yield compared to ORFV-CBPΔ-EGFP and the wild-type control. Similarly, in vivo analysis revealed no virus yield in the goat skin biopsy infected by ORFV-VEGFΔ-EGFP, and significantly reduced the virus yield of ORFV-CBPΔ-EGFP relative to the wild-type control. These results confirmed the loss of virulence of both deletion mutants in the Hoping strain, whereas the VEGF-deletion mutant was more attenuated than the CBP deletion strain in both cell and goat models. KEY POINTS: • VEGF and CBP genes are crucial in ORFV pathogenesis in the TW/Hoping strain • The VEGF-deletion mutant virus was severely attenuated in both cell culture and animal models • Deletion mutant viruses are advantageous vectors for the development of vaccines and therapeutic regimens.

Identification, molecular characterization, and pathological features of orf virus in sheep and goats in Punjab province, Pakistan.

Orf virus (ORFV) causes an acute, contagious, skin disease of sheep and goats which is economically important. The objectives of this study were to identify ORFV and to explore its pathological and phylogenetic profiles in 350 goats and 91 sheep of 14 districts of Punjab, Pakistan, from July 2020 to July 2021. Skin scrapings (total no. of samples = 441) of suspected animals were subjected to polymerase chain reactions, phylogenetic analysis, and pathological observations. The partial length of GIF/IL-2 gene (408 bp) was successfully amplified in 58/441 samples. Phylogenetic analysis of GIF/IL2 gene showed that the study isolates belonged to ORFV-cluster I, together with the viruses reported in India and China. Pakistan ORFV isolates were shared 97.6-98.7% nucleotide and 97.6-100% amino acid identities with the reference strain (NC_005336). Moreover, Chinese ORFV-isolates were detected unique multiple amino acid substitutions (F11L, Q21H, D27N, I46V, N49S, N82D, D103N, S129G) with study isolates. Naturally infected animals were anorexic, emaciated, dull, and depressed. The macroscopic lesions included multifocal to coalescing, ulceration followed by proliferative papules, pustules, and crust formation on the epidermis of gums, lips, mouth commissure, muzzles, nose, and udder. Histopathological examination revealed hyperplasia, anastomosing rete ridges formation and degenerative changes, including spongiosis and vacuolation of epidermal cells. Keratinocytes exhibited eosinophilic intracytoplasmic inclusion bodies with pyknotic and karyorrhexis nuclei. This is the first report on molecular characterization of ORFV from Pakistan, with insight into its pathogenesis and comparative analysis of pathological alterations and genetic diversity between ORFV strains reported in different geographical areas.

Construction and characterization of a contagious ecthyma virus double-gene deletion strain and evaluation of its potential as a live-attenuated vaccine in goat.

Contagious ecthyma is a highly contagious viral disease with zoonotic significance caused by orf virus (ORFV) that affects domestic, ruminants and humans. Live attenuated virus and attenuated tissue culture vaccines are widely used in the fight against ORFV, however, the conventional attenuated vaccine strains have many drawbacks. The aim of this project was to construct a promising contagious ecthyma vaccine strain with safety, high protection efficacy and accessibility by genetic manipulation to against the disease. Using a natural ORFV-GS14 strain as the parental virus, recombinant virus, rGS14-ΔCBP-ΔGIF, with double deletions in the genes encoding the chemokine binding protein (CBP) and granulocyte/macrophage colony-stimulating factor inhibitory factor (GIF) was generated and characterized in vitro and in vivo. Results showed that the growth kinetics curve of rGS14-ΔCBP-ΔGIF and parental virus was consistent, both reaching plateau phase at 48 h post infection, which indicated that the double deletion of cbp and gif genes had little impact on the replication properties of the recombinant virus in primary goat testis (PGT) cell cultures compared with the parental virus. The safety of the double gene-deleted virus was evaluated in lambs. The lambs were monitored for 21 days post infection of the recombinant virus and no ORFV associated symptoms were observed in 21 days post-infection except for slight fever and anorexia in 5 days post-infection, and all lambs inoculated with either recombinant virus or PBS exhibited no clinical signs. To assess the protection efficacy of the rGS14-ΔCBP-ΔGIF, groups of four lambs each were inoculated with rGS14-ΔCBP-ΔGIF, rGS14-ΔCBP, rGS14-ΔGIF or PBS and challenged by a wild type virulent ORFV strain that was isolated from proliferative scabby lesions tissues of infected goat at 21-day post-inoculation. During 14 days post-challenging, lambs inoculated with rGS14-ΔCBP-ΔGIF all remained healthy with unimmunized group all infected, while the single gene-deleted viruses only protected 40% to 50% animals. These results indicated that the double gene-deleted recombinant virus could provide complete protection against virulent ORFV challenging. In conclusion, the double gene-deleted recombinant virus strain, rGS14-ΔCBP-ΔGIF, would be a promising candidate vaccine strains with safety, high protection efficacy and availability.

Solitary Subungual Orf.

Orf-ecthyma contagiosum-is an endemic cutaneous disease caused by parapoxvirus that is transmitted via direct contact with contagious animals. The lesions are located frequently on the hands and fingers. Subungual presentation of orf is very rare. We report a case of solitary subungual orf. Suspicious subungual nodular lesions may be cases of orf, especially in endemic areas. Orf disease should be considered in the differential diagnosis of subungual nodular lesions to avoid unnecessary surgical interventions.

Interleukin-17 mediates inflammatory tissue injury during orf development in goats.

Orf is an epithelial zoonotic infectious disease caused by orf virus (ORFV). Mounting studies have shown that IL-17-driven neutrophil inflammation plays a central role in inflammatory skin diseases. However, whether IL-17 plays a similar role and how does it work in the pathogenesis of orf is unclear. In this study, we found that during orf development, numerous inflammatory cells, especially neutrophils, infiltrated in the damaged lip tissue. Meanwhile, the production of IL-17 was increased in the lesion site. Further evidence showed that IL-17 potently stimulated the production of several chemokines that are crucial for neutrophil migration. In addition, IL-17 was mostly produced by CD4+ T cells and gamma delta T (γδ T) cells of the skin. In conclusion, the present study highlighted a critical role of IL-17-driven inflammation in the pathogenesis of orf and suggested that this cytokine may be a potential therapeutic target of this disease in goats.

Orf progressiva: giant progressive and destructive infections in the immunocompromised.

Orf virus causes a self-limited infection in humans that resolves without scarring within 6-12 weeks. However, lesions in the immunocompromised can be progressive and disfiguring. The lesions frequently recur after treatment. To our knowledge, there are eleven published cases of these infections. We propose the name orf progressiva to call attention to this progressive, treatment-resistant entity. We present a 43-year-old male ranch owner with a history of renal transplantation who contracted an orf infection from his lamb. The infection recurred despite attempts at debridement, but achieved near complete resolution after treatment with imiquimod and valacyclovir. The histologic findings of orf progressiva are identical to the early stages of classic orf infection and are characterized by epithelial hyperplasia, intracytoplasmic eosinophilic inclusions, and an edematous, vascular dermis. There is no standard treatment for orf progressiva. Surgical excision has frequently resulted in rapid reoccurrence. Topical therapies such as imiquimod and cidofovir cream in combination with excision have been successful in some cases. Acyclovir or valacyclovir with imiquimod has been reported to be effective. Two patients achieved cure with imiquimod alone. We summarize these cases to prompt recognition of orf progressiva as a distinct clinical entity that requires treatment.

Dysbiosis of the gut microbiota maybe exacerbate orf pathology by promoting inflammatory immune responses.

Orf is a contagious disease caused by the epitheliotropic orf virus (ORFV) that mainly affects goats and sheep. Orf occurs worldwide and can cause great losses to livestock production. Mounting evidence has shown that gut microbiota plays a pivotal role in shaping the immune responses of the host and thus affecting the infection process of a wide range of pathogens. However, it is unclear whether gut microbiota plays a role during orf development. In this study, we exploited asymptomatic ORFV-carrier goats to explore the potential effects of gut microbiota on orf pathogenesis. The results showed that antibiotics-induced gut microbiota disruption significantly aggravated orf, as indicated by the greater disease severity and higher percentage of animals manifesting clinical orf symptoms. Further analysis suggested IL-17-induced excessive neutrophil accumulation in the diseased lips was potentially responsible for the tissue pathology. In addition, skin γδT cells may be an important source of IL-17. In conclusion, our study showed that the gut microbiota of ORFV-carrier goats plays a central role in controlling inflammatory pathology during ORFV infection, partly through suppressing IL-17-mediated local proinflammatory immune responses. This finding can provide help for elucidating the pathogenesis of orf and also suggests an efficient strategy to minimize the inflammatory pathology by maintaining a healthy gut microbiota during orf development.

Nódulo eritematoso en un niño / Erythematous nodule in a child

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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.