Recent isolates of parapoxvirus of Finnish reindeer (Rangifer tarandus tarandus) are closely related to bovine pseudocowpox virus

Equine dermatitis outbreak associated with parapoxvirus

Parapoxviruses (PPV) cause skin and mucous membrane lesions in several animal species, and of the five recognized PPVs, at least three are zoonotic. Equine PPV (EqPPV) is the sixth one initially described in humans in the United States and later in a severely sick horse in Finland in 2013-2015. In 2021-2022, a large-scale pustulo-vesicular pastern dermatitis outbreak occurred in horses all over Finland. This study aimed at analysing the outbreak, identifying and describing the causative agent, describing clinical signs, and searching for risk factors. EqPPV was identified as a probable causative agent and co-infections with several potentially pathogenic and zoonotic bacteria were observed. Histopathologically, suppurative and ulcerative dermatitis was diagnosed. Due to the lack of specific tests for this virus, we developed a novel diagnostic EqPPV-PCR with sensitivity of 10 copies/reaction. Based on a large proportion of the genome sequenced directly from clinical samples, very little variation was detected between the sequences of the case from 2013 and the cases from 2021 to 2022. Based on an epidemiological survey, the main risk factor for pastern dermatitis was having racehorses. Approximately one third of the horses at each affected stable got clinical dermatitis, manifesting as severe skin lesions. Skin lesions were also occasionally reported in humans, indicating potential zoonotic transmission. Case stables commonly reported attendance at race events before acquiring the disease. Survey also identified differences in practises between case and control stables. Taken together, these results enable a better preparedness, diagnostics, and guidelines for future outbreaks.

A Screening for Virus Infections among Wild Eurasian Tundra Reindeer (Rangifer tarandus tarandus) in Iceland, 2017-2019

A winter population of around 4000-5000 wild Eurasian tundra reindeer (Rangifer t. tarandus) in the eastern part of Iceland represents descendants from 35 semi-domesticated reindeer imported to Iceland from Finnmark county, Norway, in 1787. While previous studies have indicated that they host fewer parasite species as compared to reindeer in Fennoscandia, little information exists on their exposure to reindeer viral pathogens. The aim of this study was to investigate blood from hunted reindeer for antibodies against alphaherpesvirus and gammaherpesviruses (malignant catarrhal fever viruses, MCFV), pestivirus, bluetongue virus, and Schmallenberg virus, and to investigate nasal and oral mucosal membrane swab samples for the presence of parapoxvirus-specific DNA. Blood samples collected during the hunting seasons in 2017 (n = 40), 2018 (n = 103), and 2019 (n = 138) were tested for viral antibodies using enzyme-linked immunosorbent assays (ELISA). Screening for parapoxvirus DNA was conducted on swab samples from 181 reindeer by polymerase chain reaction (PCR), targeting the B2L and GIF genes. Antibodies against pestivirus were detected in two animals from 2017, and antibodies against MCFV were detected in two reindeer from 2018. No antibodies were detected against the other viruses tested. Parapoxvirus-specific DNA was detected in nasal swab samples from two animals sampled in 2019. This study suggests that the investigated viral infections are either not present or present at a low prevalence only, probably not representing a major health threat to this reindeer population. The lack of exposure to alphaherpesvirus, an enzootic pathogen in most investigated Rangifer populations, was unexpected.

Veterinarians as a Risk Group for Zoonoses: Exposure, Knowledge and Protective Practices in Finland

Background

Veterinarians may encounter a variety of zoonotic pathogens in their work.

Methods

We conducted two cross-sectional questionnaire studies among veterinarians in Finland. Participants were recruited during two Annual Veterinary Congresses. In 2009, 306 veterinarians participated in an extensive questionnaire study, and in 2016, 262 veterinarians participated in a more focused study that included two same questions.

Results

In 2009, the majority (90.9%) of the participating veterinarians reported having been occupationally exposed to zoonotic pathogens. Zoonotic infections (15.0%), needle stick incidents (78.8%), bites (85.0%), as well as infected skin lesions (24.2%) were reported. In 2009, 8.2% of the participants fully agreed with the statement “I have good knowledge of zoonoses and their prevention”; in 2016, the proportion was 10.3%. The reported use of protective practices and personal protective equipment in connection with specific veterinary procedures indicated that there was room for improvement, particularly in protection from pathogens that are transmissible via inhalation and mucous membranes.

Conclusion

The results confirm that veterinarians are commonly occupationally exposed to zoonotic pathogens. Education should aim to improve and maintain the knowledge of zoonoses and their prevention. Use of protective practices should be advocated.

Pseudocowpox virus infection in an American bison (Bison bison)

Background

The present report describes a case of pseudocowpox virus (PCPV) infection in a seven-year-old female bison euthanized due to a history of declining condition and sores on the vulva and udder.

Case presentation

External examination revealed multifocal, raised, keratinized plaques (0.5–2 cm) covering the skin of the ventral surface of the tail, perineum, caudoventral abdomen, udder, both inguinal recesses, and the medial aspects of both thighs. No significant gross lesions were present in the reminder of the tissues examined. Histopathological examination of the affected skin showed moderate epidermal hyperplasia with rete pegs, marked parakeratotic hyperkeratosis with crusts of degenerate neutrophils and cell debris, and few epithelial cells undergoing ballooning degeneration with occasional eosinophilic intracytoplasmic inclusion bodies (3–5 μm Bollinger body). Negative staining electron microscopy from skin revealed typical Parapoxvirus (PPV) particles, which were also confirmed by real-time PCR (Ct =18.6). Metagenomic analysis of the skin samples revealed only poxviruses. The bison parapox B2L envelope gene clustered with other parapox sequences identified from ruminants.

Conclusions

This is the first report of PCPV virus infection in an American bison. Identification of novel susceptible hosts of parapox viruses sheds light on the viral evolution and highlights the importance of potential economic impact of this disease to the bison industry.

Epitheliotropic Infections in Wildlife Ruminants From the Central Alps and Stelvio National Park

The mountain chain of the Alps, represents the habitat of alpine fauna where the red deer (Cervus elaphus) population is the outmost numerous, followed by the chamois (Rupicapra rupicapra) and the alpine ibex (Capra ibex) at higher altitudes. Previous reports showed the circulation of epitheliotropic viruses, belonging to the families Papillomaviridae and Poxviridae, causing skin and mucosal lesions in wild ruminants of the Stelvio National Park, situated in the area. To deepen our knowledge on the natural dynamics of the infections, a passive surveillance on all the cases of proliferative skin and mucosal lesions in wild ruminants was performed. Twenty-seven samples (11 chamois, 10 red deer and 6 ibex) collected from 2008 to 2018 were analyzed by negative staining electron microscopy, histology, and PCR followed by genome sequencing and phylogenetic analyses. Results confirmed the spread of Parapoxvirus of Red Deer in New Zealand (PVNZ) in Italy, and its ability to cause severe lesions i.e., erosions and ulcers in the mouth. We showed for the first time a PVNZ/CePV1v (C. elaphus papillomavirus 1 variant) co-infection identified in one red deer. This result supports previous evidence on the ability of papillomavirus and parapoxvirus to mutually infect the same host tissue. Interestingly two ibex and one chamois showing orf virus (OV) skin lesions were shown to be co-infected with bovine papillomavirus type 1 and 2. The presence of bovine papillomavirus, in orf virus induced lesions of chamois and ibex raises the question of its pathogenetic role in these animal species. For the first time, OV/CePV1v co-infection was demonstrated in another chamois. CePV1v is sporadically reported in red deer throughout Europe and is considered species specific, its identification in a chamois suggests its ability of cross-infecting different animal species. Poxviruses and papillomavirus have been simultaneously detected also in the skin lesions of cattle, bird and human suggesting a possible advantageous interaction between these viruses. Taken together, our findings add further information on the epidemiology and pathogenetic role of epitheliotropic viruses in wild ruminants living in the central Alps and in Stelvio National Park.

Field investigation and phylogenetic characterization of orf virus (ORFV) circulating in small ruminants and Pseudocowpoxvirus (PCPV) in dromedary camels of eastern Sudan

In this study, livestock herders in eastern Sudan were interviewed through structured questionnaire involved 14046 animals in 151 herds (87 camel herds, 51 sheep and 13 goats) from June to September of 2016 in Showak area of Gadarif State to get some epidemiological information on contagious ecthyma (CE) infection. 102 suspected cases of CE were investigated (38 sheep, 22 goats and 42 camels) by a second questionnaire focusing on age and sex of affected animals beside number and localization of the lesions. Representative tissue samples of scab lesion scrapings were collected from a total of 36 suspected sheep, goats and camels for DNA extraction to identify PPV by quantitative real-time PCR and gel-based PCR, then a PCR protocol was used to obtain DNA fragment of B2L gene from six DNAs (2 from each animal species) for sequencing. Phylogenetic tree based on nucleotide sequences was constructed and all data were analyzed statistically. Obtained result has shown morbidity rate of 23.8% and a case fatality rate of 4.7 % in overall investigated animals resulting in a significant economic loss. Within individual herd, the morbidity rate varied from 5.6 to 42.8%, while the case fatality rate ranged between 0 and 33.3%. Camels accounted for the highest case fatality rate with 6.5% compared to sheep and goats which their rates were 2.8% and 1.3%, respectively. 93% of the affected animals were young less than one-year-old. The prevalence of CE was high in the rainy season compared to winter and summer. Out of 36 scab materials collected from sheep, goats, and camels, 24 gave positive specific amplification in real-time PCR and 21 in the gel-based PCR. DNA sequencing confirmed the PCR results. All sequences had a high G + C content of 62.6-63.9%. A BLAST search also revealed that the studied sheep PPV (SPPV) isolates shared 99.08% nucleotide sequence intragroup identity, 96.88-97.27% identity with the goat PPV (GPPV) isolates and together they belong to the Orf virus (ORFV) species, while the camel PPV (CPPV) isolates are close to the Pseudocowpoxvirus (PCPV) species of the PPV genus and share 92.51-93.62 % identity with the GPPV isolates. In conclusion the present study demonstrated that the gross lesion produced by PPV in sheep, goats and camels is generally similar, yet the PPVs circulating in eastern Sudan in camels (PCPV) are genetically distinct from those affecting sheep and goats (ORFV). Contagious ecthyma in eastern Sudan causes significant morbidities and mortalities and control measures, guided by the results of this investigation ought to be implemented.

Infectious Disease Outbreak Associated With Supplementary Feeding of Semi-domesticated Reindeer

Supplementary winter feeding of semi-domesticated reindeer (Rangifer tarandus tarandus) has become more common in Sweden and Norway due to reindeer pasture fragmentation and climatic conditions. With increased corralling and feeding, often associated with animal stress, increased animal-to-animal contact, and poor hygienic conditions, an altered range of health challenges and diseases may emerge. An outbreak of three different infectious diseases appeared simultaneously in a reindeer herd in Norrbotten County, Sweden. The animals were corralled and fed silage. Several animals in poor body condition stopped eating, with drool and discoloration of the hair coat around the mouth. There were large, black, necrotic lesions on the tongue and gingiva, with holes perforating the chin, indicative of oral necrobacillosis and Fusobacterium spp. infection. Simultaneously, animals were seen with proliferative lesions in the oral mucosa and on the lips, characteristic of contagious ecthyma and Orf virus infection. Furthermore, three animals had keratoconjunctivitis suggesting exposure to cervid herpesvirus 2 (CvHV2) and possibly secondary bacterial infections. DNA specific for Fusobacterium necrophorum and ORFV was detected in relevant tissue samples. Antibodies against CvHV2 were detected in 10 of 13 diseased and in four of 11 apparently healthy reindeer. Nine animals were found dead or were euthanized during the outbreak. Health risk factors associated with feeding and corralling may severely impact animal welfare and the herder's economy, and may represent an underestimated cost when replacing natural grazing with feeding.

Putative parapoxvirus-associated foot disease in the endangered huemul deer (Hippocamelus bisulcus) in Bernardo O'Higgins National Park, Chile

The huemul (Hippocamelus bisulcus) is an endangered cervid endemic to southern Argentina and Chile. Here we report foot lesions in 24 huemul from Bernardo O’Higgins National Park, Chile, between 2005 and 2010. Affected deer displayed variably severe clinical signs, including lameness and soft tissue swelling of the limbs proximal to the hoof or in the interdigital space, ulceration of the swollen tissues, and some developed severe proliferative tissue changes that caused various types of abnormal wear, entrapment, and/or displacement of the hooves and/or dewclaws. Animals showed signs of intense pain and reduced mobility followed by loss of body condition and recumbency, which often preceded death. The disease affected both genders and all age categories. Morbidity and mortality reached 80% and 40%, respectively. Diagnostics were restricted to a limited number of cases from which samples were available. Histology revealed severe papillomatous epidermal hyperplasia and superficial dermatitis. Electron microscopy identified viral particles consistent with viruses in the Chordopoxvirinae subfamily. The presence of parapoxvirus DNA was confirmed by a pan-poxvirus PCR assay, showing high identity (98%) with bovine papular stomatitis virus and pseudocowpoxvirus. This is the first report of foot disease in huemul deer in Chile, putatively attributed to poxvirus. Given the high morbidity and mortality observed, this virus might pose a considerable conservation threat to huemul deer in Chilean Patagonia. Moreover, this report highlights a need for improved monitoring of huemul populations and synergistic, rapid response efforts to adequately address disease events that threaten the species.

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.

Characterization of mule deerpox virus in Florida white-tailed deer fawns expands the known host and geographic range of this emerging pathogen

Infections caused by mule deerpox virus (MDPV) have been sporadically reported in North American cervids. White-tailed deer (Odocoileus virginianus) fawns from a farm located in South Central Florida presented with ulcerative and crusting lesions on the coronary band as well as the mucocutaneous tissues of the head. Evaluation of the crusted skin lesions was undertaken using microscopic pathology and molecular techniques. A crusted skin sample was processed for virus isolation in four mammalian cell lines. The resulting isolate was characterized by negative staining electron microscopy and deep sequencing. Histopathologic evaluation of the skin lesions from the fawns revealed a hyperplastic and proliferative epidermis with ballooning degeneration of epidermal and follicular keratinocytes with intracytoplasmic eosinophilic inclusions. Electron microscopy of cell culture supernatant demonstrated numerous large brick-shaped particles typical of most poxviruses. Polymerase chain reaction assays followed by Sanger sequencing revealed a poxvirus gene sequence nearly identical to that of previous strains of MDPV. The full genome was recovered by deep sequencing and genetic analyses supported the Florida white-tailed deer isolate (MDPV-F) as a strain of MDPV. Herein, we report the first genome sequence of MDPV from a farmed white-tailed deer fawn in the South Central Florida, expanding the number of locations and geographic range in which MDPV has been identified.

Orf virus infection in Alaskan mountain goats, Dall's sheep, muskoxen, caribou and Sitka black-tailed deer

Background

The zoonotic Orf virus (ORFV; genus Parapoxvirus, Poxviridae family) occurs worldwide and is transmitted between sheep and goats, wildlife and man. Archived tissue samples from 16 Alaskan wildlife cases, representing mountain goat (Oreamnos americanus, n = 8), Dall’s sheep (Ovis dalli dalli, n = 3), muskox (Ovibos moschatus, n = 3), Sitka black-tailed deer (Odocoileus hemionus sitkensis, n = 1) and caribou (Rangifer tarandus granti, n = 1), were analyzed.

Results

Clinical signs and pathology were most severe in mountain goats, affecting most mucocutaneous regions, including palpebrae, nares, lips, anus, prepuce or vulva, as well as coronary bands. The proliferative masses were solid and nodular, covered by dark friable crusts. For Dall’s sheep lambs and juveniles, the gross lesions were similar to those of mountain goats, but not as extensive. The muskoxen displayed ulcerative lesions on the legs. The caribou had two ulcerative lesions on the upper lip, as well as lesions on the distal part of the legs, around the main and dew claws. A large hairless spherical mass, with the characteristics of a fibroma, was sampled from a Sitka black-tailed deer, which did not show proliferative lesions typical of an ORFV infection. Polymerase chain reaction analyses for B2L, GIF, vIL-10 and ATI demonstrated ORFV specific DNA in all cases. Sequences from Dall’s sheep formed a separate cluster, comparable to ORFV from domestic sheep. Sequences from the other species were different from the Dall’s sheep sequences, but almost identical to each other.

Conclusions

This is the first major investigation of parapoxvirus infections in large Alaskan game species, and the first report of parapoxvirus infection in caribou and Sitka black-tailed deer. This study shows that most of the wild ruminant species in Alaska and from most parts of Alaska, can carry and be affected by ORFV. These findings call for attention to transmission of ORFV from wildlife to livestock and to hunters, subsistence harvesters, and wildlife biologists.

Electronic supplementary material

The online version of this article (10.1186/s13028-018-0366-8) contains supplementary material, which is available to authorized users.

Infection with Possible Novel Parapoxvirus in Horse, Finland, 2013

A horse in Finland exhibited generalized granulomatous inflammation and severe proliferative dermatitis. After euthanization, we detected poxvirus DNA from a skin lesion sample. The virus sequence grouped with parapoxviruses, closely resembling a novel poxvirus detected in humans in the United States after horse contact. Our findings indicate horses may be a reservoir for zoonotic parapoxvirus.

Diagnosis and phylogenetic analysis of a multifocal cutaneous orf virus with mixed bacterial infection outbreak in goats in Fujian province, China

Outbreaks of orf virus on goat farms are common in China. In this study, we investigated a severe multifocal cutaneous orf virus outbreak with a correlative mixed bacterial infection which persisted for up to 6 months, and which had a high morbidity (93.7%) and mortality (15%) among kids in a herd of crossbreed goats in Fujian province in China. The disease was diagnosed as an orf virus (ORFV XD strain) infection associating with Streptococcus pluranimalium and Staphylococcus, identified using standard virological and bacteriological techniques. Multiple sequence alignments and phylogenetic analyses of the whole ORFV 011 (B2L), 059 (F1L), 032 and 080 genes revealed that the even though the virus phylogeny was clustered in branches of conventional orf virus strains, it nonetheless evidenced high variation within this subset. Furthermore, the sequences from the ORFV 080 gene allowed us to distinguish between the different strains at a higher resolution and these observations afforded us a comparative view of the ORFV 080 gene. This is the first report describing an outbreak of severe multifocal cutaneous orf virus with associated bacterial infection in China.

Detection of pseudocowpox virus in water buffalo (Bubalus bubalis) with vesicular disease in the state of São Paulo, Brazil, in 2016

BACKGROUND

Parapoxviruses are zoonotic viruses that infect cattle, goats and sheep; there have also been reports of infections in camels, domestic cats and seals.

OBJECTIVE

The objective of this report was to describe a case of vesicular disease caused by pseudocowpox virus (PCPV) in water buffalo (Bubalus bubalis) in Brazil.

ANIMALS

Sixty buffalo less than 6 months old exhibited ulcers and widespread peeling of the tongue epithelium. There were no cases of vesicular disease in pigs or horses on the same property.

METHODS

Samples were analysed by PCR and sequencing. Phylogenetic analysis in MEGA 7.01 was reconstructed using major envelope protein (B2L) by the Tamura three-parameter nucleotide substitution model and the maximum likelihood and neighbor joining models, both with 1000 bootstrap replicates. The genetic distance between the groups was analysed in MEGA using the maximum composite likelihood model. The rate variation among sites was modeled using gamma distribution.

RESULTS

The presence of PCPV in the buffalo herd could be demonstrated in epithelium and serum. The minimum genetic distance between the isolated PCPV strain (262-2016) and orf virus and bovine papular stomatitis virus was 6.7% and 18.4%, respectively. The maximum genetic distance calculated was 4.6% when compared with a PCPV detected in a camel. Conclusions/Clinical Importance: The peculiar position of the isolated strain in the phylogenetic trees does not necessarily indicate a different kind of PCPV that infects buffalo. More samples from cattle and buffalo in Brazil must be sequenced and compared to verify if PCPV from buffalo are genetically different from samples derived from cattle.

Phylogenetic analysis of eight sudanese camel contagious ecthyma viruses based on B2L gene sequence

BACKGROUND

Camel contagious ecthyma (CCE) is an important viral disease of camelids caused by a poxvirus of the genus parapoxvirus (PPV) of the family Poxviridae. The disease has been reported in west and east of the Sudan causing economical losses. However, the PPVs that cause the disease in camels of the Sudan have not yet subjected to genetic characterization. At present, the PPV that cause CCE cannot be properly classified because only few isolates that have been genetically analyzed.

METHODS AND RESULTS

PCR was used to amplify the B2L gene of the PPV directly from clinical specimens collected from dromedary camels affected with contagious ecthyma in the Sudan between 1993 and 2013. PCR products were sequenced and subjected to genetic analysis. The results provided evidence for close relationships and genetic variation of the camel PPV (CPPV) represented by the circulation of both Pseudocowpox virus (PCPV) and Orf virus (ORFV) strains among dromedary camels in the Sudan. Based on the B2L gene sequence the available CPPV isolates can be divided into two genetic clades or lineages; the Asian lineage represented by isolates from Saudi Arabia, Bahrain and India and the African lineage comprising isolates from the Sudan.

CONCLUSION

The camel parapoxvirus is genetically diverse involving predominantly viruses close to PCPV in addition to ORFVs, and can be divided into two genetically distant lineages. Based on sequences of the B2L gene it is not possible to suggest that the viruses that cause CCE form a monophylogenetic group or species within the PPV phylogeny.

Evidence of zoonotic pseudocowpox virus infection from a cattle in Turkey

Pseudocowpox virus (PCPV) infects cattle throughout the world and has zoonotic potential. However, it is not known to infect cattle in Turkey. In August 2013, we observed ulcerative nodular swelling and pustules on udder and teats of a cow in a small village nearly Lake of Bafa, Milas, Mugla locate in southwestern part of Turkey. Interestingly, the similar lesions were also observed on skin of milkier women's hand at the same time. A PCPV strain was characterized based on the major envelop gene sequence. The phylogenetic analysis showed that the isolated strain was closely related to the members of other parapoxvirus genus. This study provides the first description of PCPV infection in Turkey.

Human infection with ORF virus from goats in China, 2012

Orf virus, which belongs to the Parapoxvirus genus, induces a zoonotic infectious disease characterized by acute, highly vascularized cutaneous pustular lesions in sheep and goats. A number of Orf outbreaks have been reported in sheep and goats in recent years, but no reports have described an Orf virus strain from humans in China. In this study, we diagnosed Orf virus infection in two people, a mother and son, in the Gansu province of China. The human Orf virus was isolated and its phylogenetic characterization was analyzed based on a complete B2L gene. The results are useful for developing prospective programs to control Orf virus infections in both goats and humans.

Comparative and retrospective molecular analysis of Parapoxvirus (PPV) isolates

Species members of the genus Parapoxvirus (PPV) within the family Poxviridae cause contagious pustular dermatitis in small ruminants (Orf virus, ORFV) and mostly mild localized inflammation in cattle (bovine papular stomatitis virus, BPSV and pseudocowpox virus, PCPV). All PPVs are known to be zoonotic, leading to circumscribed skin lesions in humans, historically known as milker's nodules. Human PPV isolates are often ill defined concerning their allocation to an animal origin. Here we present a comparative molecular analysis of a unique collection of 21 historic and recent human and animal PPV cell culture isolates (and two PPV DNA samples). Cell culture PPV propagation was restricted to primary ruminant fibroblasts and was strictly kept at low passages to avoid genomic changes by in vitro influences. For molecular arrangement of the isolate DNAs and their attribution to established PPV species DNA fragments of the PPVs were generated by two different discriminating PCR protocols, targeting the major part of the open reading frame (ORF) 011 (B2L gene) and the complete ORF 032. Multiple sequence alignments and phylogenetic analysis of both genes resulted in affiliation to the known PPV species. The sequences from the ORF 032 allowed discrimination of the isolate DNAs at a higher resolution. Human PPV isolates could be clearly assigned to the PPV species belonging to the reported or assumed animal host of transmission. For the first time, a whole PPV genome sequence comparison of a human biopsy derived virus (B029) and its ovine counterpart (B015) originating from a defined Orf outbreak in Germany is provided, revealing their well conserved relationship. Thus human PPVs can be molecularly retraced to the PPV species indicating the animal of transmission. After transmission to the human host, molecular conservation of the animal's virus peculiarities indicative for a PPV species became evident.

Comparison and phylogenetic analysis based on the B2L gene of orf virus from goats and sheep in China during 2009-2011

As a zoonotic infectious disease, orf outbreaks have been reported in China in recent years. However, molecular epidemiology analysis has not been performed for Chinese orf virus (ORFV) strains. Here, we have identified 13 ORFVs from goats and sheep in China between 2009 and 2011. Thirty-four complete B2L sequences were used to construct a phylogenetic tree to elucidate the molecular epidemiology of ORFV in China. Nucleotide sequences of B2L genes of clinical samples and attenuated vaccine strains were aligned and compared. Three genotypes were found by molecular epidemiology analysis. Amino acid substitutions were dispersed among B2 polypeptides from wild and attenuated ORFV strains.

Molecular analysis of parapoxvirus detected in eight calves in Japan

Molecular analysis of parapoxvirus envelope genes was performed. Parapoxvirus DNA was detected in eight calves from eight farms in Iwate Prefecture, Japan, between April and September 2010. Seven of the detected viruses were identified as bovine papular stomatitis virus (BPSV) by sequencing, because their nucleotide identity was more than 96.8% similar compared with BPSV strain V660. Among them, two formed a subgroup, because their amplicons were digested with Xmn I (a marker for BPSV) and Hinc II and exhibited a T61C nucleotide substitution in the sequenced region. The remaining virus was pseudocowpox virus that had not been reported previously in Japan. Our results demonstrate the presence of a new BPSV variant in Japan with genetic variability in the envelope gene.

Surveillance of parapoxvirus among ruminants in Virginia and Connecticut

In 2008, two deer hunters in Virginia and Connecticut were infected with a unique strain of pseudocowpox virus, a parapoxvirus. To estimate the prevalence of this virus, and in an attempt to define the reservoir, Parapoxvirus surveillance was undertaken between November 2009 and January 2010. 125 samples from four ruminant species (cows, goat, sheep and white-tailed deer) were collected in Virginia, and nine samples from white-tailed deer were collected in Connecticut. We found no evidence that the parapoxvirus species that infected the deer hunters is circulating among domesticated ruminants or white-tailed deer. However, parapoxvirus DNA of a different parapoxvirus species, bovine papular stomatitis virus (BPSV), was detected in 31 samples obtained from asymptomatic cattle in Virginia. Parapoxvirus DNA-positive cattle originated from the same counties indicating probable transmission among animals. Molecular analysis identified BPSV as the parapoxvirus affecting animals. Asymptomatic parapoxvirus infections in livestock, particularly young animals, may be common, and further investigation will inform our knowledge of virus transmission.

Orf in South Africa: endemic but neglected

A survey amongst sheep and goat producers and veterinarians was undertaken to collect epidemiological data on orf in South Africa. Previous epidemiological studies on the presence of the disease in the country have not been documented and this report is the first descriptive epidemiological study of orf in South Africa. A seven-month investigation, realised by direct and indirect interviews and field observation, enabled us to outline incidence and risk factors of this disease and to better understand how the local farmers in rural areas relate to it. The results may contribute to better management of the disease in rural areas. By means of molecular analyses the phylogenetic relationships between field isolates from different areas have been identified. The findings gave a first important contribution to the general assessment of the economic impact of orf virus infections and the extent of the risk to human health.

Experimental parapoxvirus infection (contagious ecthyma) in semi-domesticated reindeer (Rangifer tarandus tarandus)

Contagious ecthyma (contagious pustular dermatitis, orf) occurs world-wide in sheep and goats and is caused by orf virus (genus Parapoxvirus, family Poxviridae). Contagious ecthyma outbreaks have been described in semi-domesticated reindeer (Rangifer tarandus tarandus) in Sweden, Finland and Norway, occasionally with high mortality. Fourteen one-year-old reindeer were corralled in mid-April. One week after arrival, two animals received a commercial live orf virus vaccine for sheep (Scabivax(®)) on scarified skin of the medial thigh. Four weeks later, the two vaccinated and six additional animals were inoculated in scarified oral mucosa with parapoxvirus obtained from reindeer with clinical contagious ecthyma. The remaining six reindeer were kept as sentinels, sharing feed and water with the inoculated animals. A small whitish lesion appeared on the inoculation site and the labial skin-mucosa junction of three animals five days post inoculation (p.i.). Twelve days p.i., typical ecthyma lesions were visible on the inoculation site in six of eight animals, including both vaccinees. Four inoculated animals (including both vaccinees) and one sentinel seroconverted 12 days p.i., and five animals (including one sentinel) seroconverted 20 days p.i. No contagious ecthyma-like lesions were detected in the sentinels. All animals were euthanized at 26-29 days p.i. Histological examination of lesions showed proliferative dermatitis with epidermal hyperplasia, hyperkeratosis, intra-epithelial pustules and ulcers. Orf virus DNA was detected in mandibular lymph nodes, tonsils and mucosal lesions of four animals, including one sentinel, which showed that virus transmission took place. The commercial orf virus vaccine may be difficult to administer due to the need for close-cropping and its zoonotic nature, and did not indicate significant protection, although the latter has to be verified with a larger number of animals.

Phylogenetic analysis of strains of Orf virus isolated from two outbreaks of the disease in sheep in Greece

Background

Although orf is endemic around the world, there are few descriptions of Orf virus strains and comparisons of these strains. We report the sequence and phylogenetic analysis of the partial B2L gene of Orf virus from two outbreaks of the disease in Greece. The first was an outbreak of genital form of the disease in a flock imported from France, whilst the second was an outbreak of the disease in the udder skin of ewes and around the mouth of lambs in an indigenous flock.

Results

Phylogenetic analysis was performed on a part (498 bp) of the B2L gene of 35 Parapoxvirus isolates, including the two Orf virus isolates recovered from each of the two outbreaks in the present study. This analysis revealed that the maximum nucleotide and amino-acid variation amongst Orf virus strains worldwide (n = 33) was 8.1% and 9.6%, respectively. The homology of the nucleotide and amino-acid sequences between the two Greek isolates was 99.0% and 98.8%, respectively. The two Greek isolates clustered only with Orf virus strains.

Conclusions

We suggest that there can be differences between strains based on their geographical origin. However, differences in the origin of strains or in the clinical presentation of the disease may not be associated with their pathogenicity. More work is required to determine if differing clinical presentations are linked to viral strain differences or if other factors, e.g., flock immunity, method of exposure or genetic susceptibility, are more important to determine the clinical presentation of the infection.

Original findings associated with two cases of bovine papular stomatitis

Bovine papular stomatitis virus was isolated from two calves in an animal house with biosafety level 3 confinement. The hypotheses on the origin of the infection, the interesting features of the partial amino acid sequences of the major envelope viral protein, and the importance of diagnostic tools available for animal diseases that are not listed by the World Organization for Animal Health (OIE) are discussed.

Parapoxvirus infections of red deer, Italy

To characterize parapoxviruses causing severe disease in wild ruminants in Stelvio Park, Italy, we sequenced and compared the DNA of several isolates. Results demonstrated that the red deer isolates are closely related to the parapox of red deer in New Zealand virus.

Novel deer-associated parapoxvirus infection in deer hunters

Parapoxviruses are a genus of the double-stranded DNA family of poxviruses that infect ruminants, and zoonotic transmission to humans often results from occupational exposures. Parapoxvirus infection in humans begins with an incubation period of 3 to 7 days, followed by the development of one or more erythematous maculopapular lesions that evolve over the course of several weeks into nodules. In 2009, parapoxvirus infection was diagnosed in two deer hunters in the eastern United States after the hunters had field-dressed white-tailed deer. We describe the clinical and pathological features of these infections and the phylogenetic relationship of a unique strain of parapoxvirus to other parapoxviruses. Deer populations continue to increase, leading to the possibility that there will be more deer-associated parapoxvirus infections.

Phylogenetic analysis of Croatian orf viruses isolated from sheep and goats

BACKGROUND

The Orf virus (ORFV) is the prototype of the parapoxvirus genus and it primarily causes contagious ecthyma in goats, sheep, and other ruminants worldwide. In this paper, we described the sequence and phylogenetic analysis of the B2L gene of ORFV from two natural outbreaks: i) in autochthonous Croatian Cres-breed sheep and ii) on small family goat farm.

RESULTS

Sequence and phylogenetic analyses of the ORFV B2L gene showed that the Cro-Cres-12446/09 and Cro-Goat-11727/10 were not clustered together. Cro-Cres-12446/09 shared the highest similarity with ORFV NZ2 from New Zealand, and Ena from Japan; Cro-Goat-11727/10 was closest to the HuB from China and Taiping and Hoping from Taiwan.

CONCLUSION

Distinct ORFV strains are circulating in Croatia. Although ORFV infections are found ubiquitously wherever sheep and goats are farmed in Croatia, this is the first information on genetic relatedness of any Croatian ORFV with other isolates around the world.

Diagnosis and phylogenetic analysis of Orf virus from goats in China: a case report

Background

Orf virus (ORFV) is the etiological agent of contagious pustular dermatitis and is the prototype of the genus Parapoxvirus (PPV). It causes a severe exanthematous dermatitis that afflicts domestic and wild small ruminants.

Case presentation

In the present study, an outbreak of proliferative dermatitis in farmed goats. The presence of ORFV in tissue scrapings from the lips was confirmed by B2L gene polymerase chain reaction (PCR) amplification. The molecular characterization of the ORFV was performed using PCR amplification, DNA sequencing and phylogenetic analysis of the B2L gene.

Conclusion

The results of this investigation indicated that the outbreak was caused by infection with an ORFV that was closely related genetically to Nantou (DQ934351), which was isolated from the Tai wan province of China and Hoping (EU935106), which originated from South Korea in 2008. This is the first report of the phylogenetic analysis of ORFV from goats in China.

Molecular and virological studies on contagious pustular dermatitis isolates from Egyptian sheep and goats

Orf virus was clinically diagnosed from different field cases of sheep and goat in Hawamdia, Giza, Egypt during the summer 2006. Skin scabs were collected and used for virus isolation, electron microscopy, PCR and sequencing for confirmation, and differential diagnosis. The aetiological virus was fruitfully isolated on the chorio-allantoic membrane of SPF embryonated chicken eggs indicated by expressing the characteristic pock lesions of Poxviridae family. Electron microscopy examination exposed negatively stained oval-shape virus particles trait for members of the genus Parapoxvirus. A 392 bp fragment of the late transcription factor (VLTF-1) gene of orf virus was amplified by PCR from the DNA extracted from the isolates. Phylogenetic analysis revealed 99% identity with other orf virus strains reported worldwide. Selection and processing of clinical specimens and PCR assay applied in this endeavor, presented a reliable laboratory diagnostic tool for orf infections and first molecular characterization of Egyptian orf isolates.

The genome of pseudocowpoxvirus: comparison of a reindeer isolate and a reference strain

Parapoxviruses (PPV), of the family Poxviridae, cause a pustular cutaneous disease in sheep and goats (orf virus, ORFV) and cattle (pseudocowpoxvirus, PCPV and bovine papular stomatitis virus, BPSV). Here, we present the first genomic sequence of a reference strain of PCPV (VR634) along with the genomic sequence of a PPV (F00.120R) isolated in Finland from reindeer (Rangifer tarandus tarandus). The F00.120R and VR634 genomes are 135 and 145 kb in length and contain 131 and 134 putative genes, respectively, with their genome organization being similar to that of other PPVs. The predicted proteins of F00.120R and VR634 have an average amino acid sequence identity of over 95%, whereas they share only 88 and 73% amino acid identity with the ORFV and BPSV proteomes, respectively. The most notable differences were found near the genome termini. F00.120R lacks six and VR634 lacks three genes seen near the right terminus of other PPVs. Four genes at the left end of F00.120R and one in the middle of both genomes appear to be fragmented paralogues of other genes within the genome. VR634 has larger than expected inverted terminal repeats possibly as a result of genomic rearrangements. The high G+C content (64%) of these two viruses along with amino acid sequence comparisons and whole genome phylogenetic analyses confirm the classification of PCPV as a separate species within the genus Parapoxvirus and verify that the virus responsible for an outbreak of contagious stomatitis in reindeer over the winter of 1999-2000 can be classified as PCPV.

Recurrent localised cutaneous parapoxvirus infection in three cats

CASE HISTORY

Three cats were presented with single proliferative lesions affecting one foot, which failed to heal after medical treatment, and recurred despite surgical resection.

PATHOLOGICAL FINDINGS

Histologically, the lesions were proliferative and papillary. There was marked acanthosis, rete peg formation, and compact orthokeratosis, with large numbers of bacteria in the orthokeratotic scale. Some biopsies had multifocal keratinocyte swelling of the stratum granulosum, and amphophilic intracytoplasmic inclusions were present in some of the swollen cells. The dermis consisted of a light fibrous stroma with marked capillary proliferation. Parapoxviruses were detected in the lesions of all cats by electron microscopic examination. PCR analysis detected orf virus (contagious ecthyma virus) in two cats, and orf virus was cultured from one cat.

DIAGNOSIS

Parapoxvirus infection in cats.

CLINICAL RELEVANCE

Parapoxvirus infection should be considered as a differential diagnosis when dealing with proliferative, non-healing lesions on the feet of cats, especially cats in rural areas. The recovery of orf virus from a cat with typical poxvirus lesions extends the range of species affected by this virus.

Identification and phylogenetic analysis of orf virus from goats in Taiwan

An outbreak of contagious ecthyma in goats in central Taiwan was investigated. The disease was diagnosed by physical and histopathologic examinations, and the etiology of the disease was identified as orf virus by electron microscopy and polymerase chain reaction (PCR) and sequence of major envelope protein (B2L) gene. The entire protein-coding region of B2L gene were cloned and sequenced. Phylogenetic analysis of B2L amino acid sequences showed that the orf virus identified in this outbreak was closer to the Indian ORFV-Mukteswar 59/05 isolate. This is the first report on the molecular characterization of orf virus in Taiwan.

Efficient priming against classical swine fever with a safe glycoprotein E2 expressing Orf virus recombinant (ORFV VrV-E2)

An increasing demand in livestock animal husbandry for intervention or emergency vaccination strategies requires a rapid onset of protection linked to prevention of infectious agent spread. Using the new recombinant parapoxvirus (PPV) Orf virus (ORFV) as a vaccine expressing the CSFV E2 glycoprotein we demonstrate that a single intra-muscular application confers solid protection. In the prime only concept, multi-site application of the vector vaccine turned out to be superior to single-site application as no pyrexia occurred after virulent CSFV challenge and CSFV neutralizing serum antibodies regularly were detectable before challenge. Vector virus vaccinated swine were able to cope with the lymphocyte and in particular B-cell depression in peripheral blood after challenge showing no clinical signs and no viremia. Early after challenge CSFV-specific IFN gamma production (IFN-gamma) and high neutralizing serum antibody titers clearly differentiated naïve from vaccinated and protected animals. After CSFV challenge neutralizing serum antibodies titers in vector vaccinated swine were significantly higher than those in sera from live attenuated vaccine primed animals. Horizontal challenge virus transmission was prevented under strict sentinel isolation before mingling but not in next-door stables separated by a wooden barrier at the day of challenge. The presence of CSFV-specific pre-challenge serum antibodies although in low titers is a good prognostic parameter for solid protection after ORFV vector vaccination even when a significant CSFV-specific IFN-gamma production was not detectable before challenge. A heterologous prime-boost regimen as a combination of prime with baculovirus-expressed glycoprotein E2 followed by boost with the parapoxvirus vector turned out to be a better immune stimulant than a homologous prime/boost with the modified live CSFV vaccine. A similar beneficial effect became evident when the challenge infection mimicked the booster vaccination after a single PPV vector prime.

Pseudocowpox Virus: The Etiological Agent of Contagious Ecthyma (Auzdyk) in Camels (Camelus dromedarius) in the Arabian Peninsula

We have determined the nucleotide sequence of DNA extracted from pustules, saliva, and blood of camels presenting with contagious ecthyma, in Bahrain and also from a sample (SACamel) of infected tissue from a camel that had presented with contagious ecthyma in 1998 in Saudi Arabia (1). Sequence homologies and phylogenetic analysis showed that this extracted DNA was more closely related to Pseudocowpox virus (PCPV) than Orf virus (ORFV), which infects sheep, goats, and other animal species. The phylogeny also demonstrated that PCPV in Arabian camels was phylogenetically distinct from, and circulates independently of, ruminant-associated PCPV from Europe.

Variation analysis of two cucumber mosaic viruses and their associated satellite RNAs from sugar beet in China

Two cucumber mosaic virus (CMV) isolates XJ1 and XJ2 were obtained from sugar beet showing yellow mosaic symptom in Shihezi, Xinjiang Uigur municipality of China. The coat protein gene of the two CMV isolates and their associated satellite RNAs were amplified by reverse transcriptase polymerase chain reaction (RT-PCR) and were cloned and sequenced. Comparison of CP gene sequences showed that XJ1 and XJ2 have the highest sequence identity with that of CMV-Danshen (97.8%) and CMV-SD (98.7%), respectively. Two types of satellite RNAs (XJs1 and XJs2) were found to be associated with the two CMV isolates consisting of 384 nucleotides and 336 nucleotides, respectively. Sequence comparisons revealed that XJs1 and XJs2 were most closely related to CS2-sat and CS1-sat, respectively, with 98.9% and 98.5% nucleotide sequence identity. Phylogenetic analysis of nucleotide sequence and deduced amino acid sequence of coat protein gene revealed that XJ1 and XJ2 belong to subgroup IB but there exist some variation between them. Parallel analyses of nucleotide sequence of XJsl and XJs2 suggested that these two satellite RNAs probably originated from China.

Genus Parapoxvirus

Highly contagious pustular skin infections of sheep, goats and cattle that were unwittingly transmitted to humans from close contact with infected animals, have been the scourge of shepherds, herdsmen and dairy farmers for centuries. In more recent times we recognise that these proliferative pustular lesions are likely to be caused by a group of zoonotic viruses that are classified as parapoxviruses. In addition to infecting the above ungulates, parapoxviruses have more recently been isolated from seals, camels, red deer and reindeer and most have been shown to infect man. The parapoxviruses have one of the smallest genomes of the poxvirus family (140 kb) yet share over 70% of their genes with the most virulent members. Like other poxviruses, the central core of the genomes encode factors for virus transcription and replication, and structural proteins, whereas the terminal regions encode accessory factors that give the parapoxvirus group many of its unique features. Several genes of parapoxviruses are unique to this genus and encode factors that target inflammation, the innate immune responses and the development of acquired immunity. These factors include a homologue of mammalian interleukin (IL)-10, a chemokine binding protein and a granulocyte-macrophage colony stimulating factor /IL-2 binding protein. The ability of this group to reinfect their hosts, even though a cell-mediated memory response is induced during primary infection, may be related to their epitheliotropic niche and the immunomodulators they produce. In this highly localised environment, the secreted immunomodulators only interfere with the local immune response and thus do not compromise the host’s immune system. The discovery of a vascular endothelial growth factor-like gene may explain the highly vascular nature of parapoxvirus lesions. There are many genes of parapoxviruses which do not encode polypeptides with significant matches with protein sequences in public databases, separating this genus from most other mammalian poxviruses. These genes appear to be involved in inhibiting apoptosis, manipulating cell cycle progression and degradation of cellular proteins that may be involved in the stress response, thus allowing the virus to subvert intracellular antiviral mechanisms and enhance the availability of cellular molecules required for replication. Parapoxviruses in common with Molluscum contagiosum virus lack a number of genes that are highly conserved in other poxviruses, including factors for nucleotide metabolism, serine protease inhibitors and kelch-like proteins. It is apparent that parapoxviruses have evolved a unique repertoire of genes that have allowed adaptation to the highly specialised environment of the epidermis.

Parapoxvirus of red deer in New Zealand encodes a variant of viral vascular endothelial growth factor

Parapoxvirus of red deer in New Zealand (PVNZ), a species of the Parapoxvirus genus, causes scabby lesions on the skin and the velvet of red deer. The three other species of the genus have each been shown to encode homologs of vascular endothelial growth factor (VEGF). We report here that PVNZ strain RD86 also encodes a VEGF and that the predicted PVNZ protein shows only 37-54% amino acid identity to VEGFs encoded by the other species of the genus. Despite this extensive sequence divergence, assays of purified PVNZ VEGF (PVNZ(RD86)VEGF) demonstrated that it shares the unique VEGF receptor (VEGFR) binding profile of the other parapoxvirus VEGFs, in that it binds VEGFR-2 and induces VEGFR-2-mediated proliferation of Ba/F3-derived cells, but does not bind VEGFR-1 or VEGFR-3. In contrast to some other viral VEGFs, it does not bind neuropilin-1. Our results indicate that PVNZ(RD86)VEGF is a biologically active member of the VEGF family and is likely to contribute to the proliferative and highly vascularized nature of PVNZ lesions. Our data also reveal that all members of the genus encode a VEGF and that an extraordinary degree of inter-species sequence variation is a general feature of the parapoxvirus VEGFs.

Genomic characterization of a novel poxvirus contributing to the decline of the red squirrel (Sciurus vulgaris) in the UK

The genome of a virulent squirrelpox virus (SQPV) isolate was characterized in order to determine its relationship with other poxviruses. Restriction enzyme analysis suggested a genome length of approximately 158 kb, whilst sequence analysis of the two ends of the genome indicated a G + C composition of approximately 66 %. Two contiguous stretches of 23 and 37 kb at the left-hand and right-hand ends of the genome, respectively, were sequenced allowing the identification of at least 59 genes contained therein. The partial sequence of a further 15 genes was determined by spot sequencing of restriction fragments located across the genome. Phylogenetic analysis of 15 genes conserved in all the recognized genera of the subfamily Chordopoxvirinae confirmed that the SQPV does not group within the family Parapoxvirinae, but instead partitions on its own in a separate clade of the poxviruses. Analysis of serum from British woodland rodents failed to find any evidence of SQPV infection in wood mice or bank voles, but for the first time serum samples from grey squirrels in the USA were found to contain antibody against SQPV.