Contagious Ecthyma Research Articles

Host range, severity and trans boundary transmission of Orf virus (ORFV).

Contagious ecthyma in small ruminants is a zoonotic disease caused by Orf virus (ORFV) in the genus Parapoxvirus that can be deadly to its natural hosts. It causes significant losses worldwide, and commonly infects humans. However, the literature about its comparative severity in sheep and goat hosts is misleading; and while contagious ecthyma has been shown to occur in camels and transmit to humans, there is confusion as to whether ORFV is responsible. Camels are important from a 'One Health' perspective as they have been implicated as a reservoir host for the virus causing Middle East Respiratory Syndrome (MERS), which has a case fatality rate of 35% in humans. We compared ORFV gene sequences and mortality data from the West Bank in Palestine, where ORFV has not been reported previously, with data from the region. Surprisingly, we found that infections of camels that had been attributed to ORFV were more closely related to a different member of the genus Parapoxvirus. Two Middle East ORFVs isolated from humans were unrelated and sat alongside sheep and goat derived sequences on two distinct ORFV lineages of a maximum likelihood B2L gene tree. One of the viral lineages bifurcated to produce a monophyletic group of goat-derived ORFVs characterized uniquely by a glycine at amino acid reside 249. We found that serine is the ancestral allele shared between ORFV infections of sheep and also two closely related Parapoxviruses (PCPV and CCEV), indicating that the glycine allele represents a more recent shift in virus host range adaptation to goats. Furthermore, and contrary to some reports that ORFV is more severe in goats than in sheep, we observed median mortality of up to 24.5% in sheep, but none in goats. We also identified trans-boundary spread of ORFV between the West Bank and Israel.

ORF Nodule Complicated by Erythema Multiforme: About 2 Cases

ORF nodule is a disease caused by a parapoxvirus ovis with epithelial tropism which is transmitted to humans from sick animals, sheep and goats, suffering from contagious ovine pustular dermatosis ecthyma [1]. Common complications of ORF infection have been reported, including secondary bacterial infection, lymphadenopathy, lymphangitis, more rarely erythema multiforme and bullous pemphigoid [2]. We describe here two cases of ORF nodule with secondary erythema multiforme.

Genetic Analysis of Orf Virus (ORFV) Strains Isolated from Goats in China: Insights into Epidemiological Characteristics and Evolutionary Patterns

Contagious ecthyma (CE) is an acute infectious zoonosis caused by orf virus (ORFV) that mainly infects sheep and goats and causes obvious lesions and low market value of livestock, resulting in huge economic losses for farmers. In this study, two strains of ORFV were isolated from Shaanxi Province and Yunnan Province in China, named FX and LX. The two ORFVs were located in the major clades of domestic strains respectively, and exhibited distinct sequence homology. We analyzed the genetic data of core genes (B2L, F1L, VIR, ORF109) and variable genes (GIF, ORF125 and vIL-10) of ORFV to investigate its epidemiological and evolutionary characteristics. The sequences from 2007 to 2018 constituted the majority of the viral population, predominantly concentrated in India and China. Most genes were clustered into SA00-like type and IA82-like type, and the hotspots in East and South Asia were identified in the ORFV transmission trajectories. For these genes, VIR had the highest substitution rate of 4.85 × 10−4, both VIR and vIL-10 suffered the positive selection pressure during ORFV evolution. Many motifs associated with viral survival were distributed among ORFVs. In addition, some possible viral epitopes have been predicted, which still require validation in vivo and in vitro. This work gives more insight into the prevalence and phylogenetic relationships of existing orf viruses and facilitate better vaccine design.

Prevalence of zoonotic diseases of small ruminants at Savar upazila of Dhaka district

The objective of this study was to assess the prevalence of zoonotic diseases of small ruminants (SR) at Savar upazila of Dhaka district. A questionnaire-based survey was conducted in small and middle-scale goat and sheep farms at Savar Upazila with a total number of 1981 SR (1438 goats and 543 sheep). We found a total of 468 diseased SR (281 goats and 187 sheep), of which 206 cases were zoonotic (41.37%) (124 / 60% goats; 82/40% sheep). Prevalence of bacterial zoonoses (Salmonellosis, Tetanus Dermatophilosis, Brucellosis, Listeriosis and Campylobacteriosis ) was higher (23.78% in goat and 15.53% in sheep) followed by that of parasitic zoonoses (Hydatidosis, Fascioliasis, Amphistomiasis and Cryptosporidiosis) (17.48% in goat and 11.65% in sheep), viral zoonoses (Contagious Ecthyma, Foot and Mouth Disease and Rabies) (12.14% in goat and 7.77% in sheep), rickettsial zoonoses (Q Fever) (2.91% in goat and 1.94% in sheep). The age-wise, sex-wise and breed-wise prevalence of zoonotic diseases in goats and sheep were also determined. The study provided an epidemiological forecast showing the prevalence of zoonotic diseases of SR, which can be helpful for the clinician in the diagnosis of such infections. The present study revealed that the SR at Savar Upazila is susceptible and also infected with various zoonotic diseases. So, prevention and control of these zoonotic diseases are essential. Bangladesh J. Agri. 2023, 48(1): 81-91

Risk analysis of contagious ecthyma outbreaks in Kazakhstan

Risk analysis of contagious ecthyma outbreaks in Kazakhstan

Construction of a Triple-Gene Deletion Mutant of Orf Virus and Evaluation of Its Safety, Immunogenicity and Protective Efficacy.

Contagious ecthyma is a zoonotic disease caused by the orf virus (ORFV). Since there is no specific therapeutic drug available, vaccine immunization is the main tool to prevent and control the disease. Previously, we have reported the construction of a double-gene deletion mutant of ORFV (rGS14ΔCBPΔGIF) and evaluated it as a vaccine candidate. Building on this previous work, the current study reports the construction of a new vaccine candidate, generated by deleting a third gene (gene 121) to generate ORFV rGS14ΔCBPΔGIFΔ121. The in vitro growth characteristics, as well as the in vivo safety, immunogenicity, and protective efficacy, were evaluated. RESULTS: There was a minor difference in viral replication and proliferation between ORFV rGS14ΔCBPΔGIFΔ121 and the other two strains. ORFV rGS14ΔCBPΔGIFΔ121 induced continuous differentiation of PBMC to CD4+T cells, CD8+T cells and CD80+CD86+ cells and caused mainly Th1-like cell-mediated immunity. By comparing the triple-gene deletion mutant with the parental strain and the double-gene deletion mutant, we found that the safety of both the triple-gene deletion mutant and the double-gene deletion mutant could reach 100% in goats, while the safety of parental virus was only 50% after continually observing immunized animals for 14 days. A virulent field strain of ORFV from an ORF scab was used in the challenge experiment by inoculating the virus to the hairless area of the inner thigh of immunized animals. The result showed that the immune protection rate of triple-gene deletion mutant, double-gene mutant, and the parental virus was 100%, 66.7%, and 28.6%, respectively. In conclusion, the safety, immunogenicity, and immune-protectivity of the triple-gene deletion mutant were greatly improved to 100%, making it an excellent vaccine candidate.

Relationship between Vaccine Application and Climate Factors in Sheep and Goat Farms in Greece.

The objectives of the present study were (a) to evaluate the importance of climate-related variables in the vaccination patterns applied in sheep and goat farms in Greece and (b) to assess potential interactions between these factors and previously established important health management- and human resources-related factors applied in the farms. Vaccination patterns against chlamydial abortion, clostridial infections, contagious agalactia, contagious ecthyma, foot-rot, paratuberculosis, pneumonia or staphylococcal mastitis were assessed. Climatic variables (2010-2019 and 2018-2019) were obtained for 444 locations with small ruminant farms throughout Greece. Patterns of vaccine administration in the farms were obtained through interviews with farmers. The following nine outcomes were considered: 'vaccination against chlamydial abortion', 'vaccination against clostridial infections', 'vaccination against contagious agalactia', 'vaccination against contagious ecthyma', 'vaccination against foot-rot', 'vaccination against paratuberculosis', 'vaccination against bacterial pneumonia', 'vaccination against staphylococcal mastitis' and 'total number of optional vaccines administered'. Univariable and multivariable analyses were first performed to establish associations of each of the above outcomes with climatic variables. Then, the same approach was employed to assess the importance of climatic variables against health management- and human resources-related factors in the administration of vaccines in the farms of the study. Climatic variables had a higher association with vaccinations against infections in sheep flocks (26 associations) than in goat herds (9 associations) (p = 0.002) and in farms with semi-extensive or extensive management (32 associations) than in farms with intensive or semi-intensive management (8 associations) (p < 0.0001). In 26 cases (38.8% of all analyses evaluated), the climatic variables overshadowed the management- and human resources-related variables assessed as significant predictors for vaccination. In most cases, these referred to sheep flocks (nine cases) and farms with semi-extensive or extensive management (eight cases). For all eight infections, there were changes in the climatic variables found to be significant predictors from the 10-year dataset to the 2-year dataset. The results indicated that, in some cases, climate factors overshadowed factors traditionally considered for the formulation of vaccination programs. This points out the significance of taking into account climate conditions in the health management of small ruminant farms. Future studies can be focused on formulating vaccination programs in accordance with climate factors and also on setting the optimum season(s) for vaccination of animals based on the circulation of the pathogens, the risks for the development of diseases and the stage within the annual production cycle of the animals.

Orf virus DNA prime-protein boost strategy is superior to adenovirus-based vaccination in mice and sheep.

Contagious ecthyma (Orf), an acute and highly contagious zoonosis, is prevalent worldwide. Orf is caused by Orf virus (ORFV), which mainly infects sheep/goats and humans. Therefore, effective and safe vaccination strategies for Orf prevention are needed. Although immunization with single-type Orf vaccines has been tested, heterologous prime-boost strategies still need to be studied. In the present study, ORFV B2L and F1L were selected as immunogens, based on which DNA, subunit and adenovirus vaccine candidates were generated. Of note, heterologous immunization strategies using DNA prime-protein boost and DNA prime-adenovirus boost in mice were performed, with single-type vaccines as controls. We have found that the DNA prime-protein boost strategy induces stronger humoral and cellular immune responses than DNA prime-adenovirus boost strategy in mice, which was confirmed by the changes in specific antibodies, lymphocyte proliferation and cytokine expression. Importantly, this observation was also confirmed when these heterologous immunization strategies were performed in sheep. In summary, by comparing the two immune strategies, we found that DNA prime-protein boost strategy can induce a better immune response, which provides a new attempt for exploring Orf immunization strategy.

Orf virus induces complete autophagy to promote viral replication via inhibition of AKT/mTOR and activation of the ERK1/2/mTOR signalling pathway in OFTu cells

Orf virus (ORFV) is the causative agent of contagious ecthyma, which is an important zoonotic pathogen with a widespread distribution affecting sheep, goats and humans. Our previous research showed that autophagy can be induced in host cells by ORFV infection. However, the exact mechanism of ORFV-induced autophagy remains unknown. In this study, we investigated the underlying mechanisms of autophagy induced by ORFV in OFTu cells and the impact of autophagy on ORFV replication. By using specific autophagy inhibitors and activators, Western blotting, immunofluorescence and transmission electron microscopy imaging, we confirmed that ORFV infection triggered intracellular autophagosome accumulation and the activation of autophagic flux. Moreover, ORFV-induced autophagic activity was found to rely on an increase in the phosphorylation of tuberous sclerosis complex 2 (TSC2) and a decrease in the phosphorylation of mammalian target of rapamycin (mTOR), which is mediated by the suppression of the PI3K/AKT/mTOR signalling pathway and activation of the ERK1/2/mTOR signalling pathway. Furthermore, we investigated the role of mTOR-mediated autophagy during ORFV replication using pharmacological agents and demonstrated that ORFV-induced autophagy correlated positively with viral replication. Taken together, our data reveal the pathways of ORFV-induced autophagy and the impact of autophagy on ORFV replication, providing new insights into ORFV pathogenesis.

O-063 Evaluation of recombinant viral-vectored vaccine against contagious ecthyma in sheep

O-063 Evaluation of recombinant viral-vectored vaccine against contagious ecthyma in sheep

P-045 Development of a therapeutic subunit vaccine for contagious ovine ecthyma

P-045 Development of a therapeutic subunit vaccine for contagious ovine ecthyma

Genetic Phylocomparative Analysis of B2L, F1L Genes in Orf Virus Isolated from Felid Infected Sheep

Contagious ecthyma virus Large, oval, double-stranded DNA viruses from the family Poxviridae they are distinct from other poxviruses due to their unusual spiral coat. Orf virus encoded highly conserved F1L gene, B2L gene, which codes for highly immunogenic envelope protein. Orf lesions were observed on the upper and lower lips, upper and/or lower eyelids, and around the mouth and nose of sheep. This study evaluated the histology and genetics of Orf virus in AL-Qadisyah sheep infected with infectious ecthyma. Positive histology is defined by the presence of subcorneal pustules, hydropic degeneration of necrotic keratinocytes, and epidermal hyperplasia with pronounced rete ridges. Samples were fixed in paraffin and sectioned into 5m slices. PCR on DNA-extracted samples was positive for both the B2L and F1L genes. Four positive samples were sequenced and recorded in GeneBank, and phylogenetic analysis was performed. Histopathology and clinical symptoms can aid in the diagnosis of infectious ecthyma rapidly and affordably, whereas PCR distinguishes between identical diseases in endemic regions. Analyzing the divergence between the inferred amino acid sequences of the incomplete B2L gene in different strains from Iraq OK336711.1, OK336710.1, and other Indians, we found that two locations contain different amino acid changes, resulting in a nucleotide and amino acid identity of 97.8% and 97.6%, respectively. The F1L envelope protein of the Iraqi strain OK330734.1 was comparable to those of China and India, while the envelope protein of the Italian strain OK330733.1 was identical to that of Italy.

O-172 Evaluation of the effect of a topical anaesthetic/antiseptic formulation for the treatment of contagious ecthyma in lambs on the concentration of serum amyloid A

O-172 Evaluation of the effect of a topical anaesthetic/antiseptic formulation for the treatment of contagious ecthyma in lambs on the concentration of serum amyloid A

O-134 Efficiency of different infection routes for the experimental reproduction of contagious ecthyma in lambs

O-134 Efficiency of different infection routes for the experimental reproduction of contagious ecthyma in lambs

O-171 Evaluation of the effect of a topical wound anaesthesia formulation used for the treatment of contagious ecthyma in lambs infected experimentally

O-171 Evaluation of the effect of a topical wound anaesthesia formulation used for the treatment of contagious ecthyma in lambs infected experimentally

Doenças virais em ovinos no Brasil: revisão e status atual

ABSTRACT: The increase in sheep production is directly related to the health status of the flock. Brazil is one of the largest sheep producers in the world, and the sheep flock is concentrated in southern and northeast regions. Infectious diseases are responsible for severe economic losses resulting from a decrease in milk and meat production, deaths, and cost of treatment. Among infectious diseases, viral diseases are described chiefly in case reports or retrospective studies. This study aimed to review the main features of viral diseases that affect sheep in Brazil and their current situation in the Brazilian territory. We included eight viral diseases described in Brazil: rabies, bluetongue, contagious ecthyma, foot and mouth disease, visna-maedi, enzootic nasal tumor, ovine pulmonary adenocarcinoma, and border disease. We review the etiological, epidemiological, clinical, and pathological findings for each agent and included differential diagnoses, information on recommended diagnostic methods to confirm the disease etiology, and control measures. This study served as quick consultation material for field veterinarians for an accurate diagnosis.

Seasonal Rhythmicity of Contagious Ecthyma in Small Ruminants

Seasonal Rhythmicity of Contagious Ecthyma in Small Ruminants

Immune Response, Gene sequence to Contagious Ecthyma Virus (Orfv) Infected Lambs in Diyala Governorate, Iraq

Contagious ecyhyma Known (Orf, contagious pustular dermatitis, sore mouth, scabby mouth) a disease spreads easily and brought by the epitheliotropic. It’s endemic around the world and has a serious economic impact. This study aimed to understand the immune response mechanisms of the lambs to defense against Contagious ecthyma virus and molecular detection of the virus with the determining the sequence and mutant of the viral genome to 91 lambs (41 has clinical signs of Orfv and 50 control do not have clinical sign of Orfv) for the period extended from September 2022 to April 2023. Blood samples were collected from all above groups to apply for detection the level of IgM, IgG, IL-10, and IFN-γ of Orfv by ELISA test. Positive Orfv IgM was 75.6% infected lamb and 72% none infected, and positive Orfv IgG was 90.2% infected lamb and 88% none infected. The result was showed the level of IL-10 a significant increasing, in all Lambs positive IgM and IgG compared with control group. IFN-γ level showed non significant differences between all Lambs positive IgM and IgG compared with control group. Molecular detection of Orfv result was confirmed the positivity of all samples positive Orfv IgM. And the sequencing of the Orfv DNA showed a mutant in the some Allel compared with References strain registered at NCBI. Concluded: high prevalence of Orfv among lambs and happened mutants to the viral genome increased the virus’s virulence by affecting the immune response.

Seroprevalence of Contagious Ecthyma and Its Associated Risk Factors in Sheep and Goats of Punjab, Pakistan

Seroprevalence of Contagious Ecthyma and Its Associated Risk Factors in Sheep and Goats of Punjab, Pakistan

Seroprevalence of Orf virus in sheep in Basrah province, Southern Iraq

Orf which is commonly referred to as contagious ecthyma is a viral infectious disease that infects small ruminants. Little is known about the disease status in our geographical region. This study aimed to determine the seroprevalence of Orf virus in sheep in Basrah province, southern Iraq. Serum samples were randomly collected from 380 sheep of different age and sex groups from 4 different regions in Basrah province, which were Zubair, Abulkhasib, Shatt Al-Arab, and Qurnah. The samples were tested by ELISA for the presence of IgG antibodies to the Orf virus. Out of 380 animals screened, 98 animals were found positive for ELISA, which reveals an overall prevalence of 25.7%. There was no significant difference in the seropositivity between male and female animals. On the other hand, the seropositivity was significantly higher in lambs of the age group 1-6 months in comparison with the other age groups (6-12 months and more than 12 months). This finding indicates that the virus is highly prevalent in Basrah province as confirmed by the ELISA test.