Diagnosis of Bovine-Associated Parapoxvirus Infections in Humans: Molecular and Epidemiological Evidence

Prevalence, clinico-epidemiological features, and molecular characterization of bovine papular stomatitis virus in cattle in Iraq

Bovine papular stomatitis virus (BPSV) is a parapoxvirus that infects cattle, causing skin lesions on the udder and mouth. There have been few studies on the prevalence and molecular characteristics of BPSV in Iraq. Here, we describe the prevalence, phylogenetic analysis, and clinico-epidemiological features of BPSV in cattle in Al-Qadisiyah, Iraq. A total of 264 animals were examined for teat and oral lesions, and BPSV was detected by PCR in 79.9% (211/264) of cattle and calves with skin lesions. The lesions included ulcers, papules, and scabby proliferative areas. The BPSV strains from Iraq clustered phylogenetically with BPSV strains detected in the USA. Further studies are needed to explore the evolution and epidemiology of this virus in the region.

Molecular detection and phylogenetic analysis of Orf viruses from goats in Jiangxi province, China

Orf is a zoonosis caused by the Orf virus (ORFV), which is endemic in goats, sheep, and wild ruminants worldwide. Orf infection is prevalent in China, with outbreaks reported in several provinces. Currently, there is limited information available regarding the characterization of ORFV strains in Jiangxi province. This study investigated an acute outbreak of Orf that occurred in 2021 in a goat herd in the Jiangxi province of China. Clinical signs in this case included lesions on the lips, nose, and inside the mouth. The presence of ORFV was confirmed from tissue samples by polymerase chain reaction (PCR). The nucleotide sequences of the B2L and F1L genes were fully sequenced and used to construct phylogenetic trees. The results of this investigation identified the ORFV JXxy2021 as the cause of the outbreak. The phylogenetic analysis revealed that the ORFV strain JXxy2021 had the highest similarity to the ORFV strains GO and FJ-SL from the neighboring province of Fujian. This suggests that JXxy2021 was likely transmitted from Fujian province. The results have provided valuable information on the genetic characteristics of JXxy2021 and the endemic situations of Orf in China.

A loop-mediated isothermal amplification assay for rapid and sensitive detection of bovine papular stomatitis virus

Bovine papular stomatitis virus (BPSV) causes pustular cutaneous disease in cattle worldwide. This paper describes the development of a specific loop-mediated isothermal amplification (LAMP) assay to detect BPSV which did not cross-react with other parapoxviruses. To assess analytical sensitivity of this LAMP assay, DNA was extracted from serially diluted BPSV from which the infectious titer was determined by a novel assay based on calf kidney epithelial cells. The LAMP assay had equivalent analytical sensitivity to quantitative PCR, and could detect as few as 86 copies of viral DNA per reaction. These results suggest that the assay is a specific and sensitive technique to rapidly diagnose bovine papular stomatitis in domestic animals.

Genome variability and gene content in chordopoxviruses: dependence on microsatellites

To investigate gene loss in poxviruses belonging to the Chordopoxvirinae subfamily, we assessed the gene content of representative members of the subfamily, and determined whether individual genes present in each genome were intact, truncated, or fragmented. When nonintact genes were identified, the early stop mutations (ESMs) leading to gene truncation or fragmentation were analyzed. Of all the ESMs present in these poxvirus genomes, over 65% co-localized with microsatellites—simple sequence nucleotide repeats. On average, microsatellites comprise 24% of the nucleotide sequence of these poxvirus genomes. These simple repeats have been shown to exhibit high rates of variation, and represent a target for poxvirus protein variation, gene truncation, and reductive evolution.

Characterization of GM-CSF-inhibitory factor and Uracil DNA glycosylase encoding genes from camel pseudocowpoxvirus

The present study describes the PCR amplification of GM-CSF-inhibitory factor (GIF) and Uracil DNA glycosylase (UDG) encoding genes of pseudocowpoxvirus (PCPV) from the Indian Dromedaries (Camelus dromedarius) infected with contagious ecthyma using the primers based on the corresponding gene sequences of human PCPV and reindeer PCPV, respectively. The length of GIF gene of PCPV obtained from camel is 795 bp and due to the addition of one cytosine residue at position 374 and one adenine residue at position 516, the open reading frame (ORF) got altered, resulting in the production of truncated polypeptide. The ORF of UDG encoding gene of camel PCPV is 696 bp encoding a polypeptide of 26.0 kDa. Comparison of amino acid sequence homologies of GIF and UDG of camel PCPV revealed that the camel PCPV is closer to ORFV and PCPV (reference stains of both human and reindeer), respectively.

Comparative sequence analysis of double stranded RNA binding protein encoding gene of parapoxviruses from Indian camels

The dsRNA binding protein (RBP) encoding gene of parapoxviruses (PPVs) from the Dromedary camels, inhabitating different geographical region of Rajasthan, India were amplified by polymerase chain reaction using the primers of pseudocowpoxvirus (PCPV) from Finnish reindeer and cloned into pGEM-T for sequence analysis. Analysis of RBP encoding gene revealed that PPV DNA from Bikaner shared 98.3% and 76.6% sequence identity at the amino acid level, with Pali and Udaipur PPV DNA, respectively. Reference strains of Bovine papular stomatitis virus (BPSV) and PCPV (reindeer PCPV and human PCPV) shared 52.8% and 86.9% amino acid identity with RBP gene of camel PPVs from Bikaner, respectively. But different strains of orf virus (ORFV) from different geographical areas of the world shared 69.5-71.7% amino acid identity with RBP gene of camel PPVs from Bikaner. These findings indicate that the camel PPVs described are closely related to bovine PPV (PCPV) in comparison to caprine and ovine PPV (ORFV).

Novel poxvirus infection in 2 patients from the United States

BACKGROUND

Some human poxvirus infections can be acquired through zoonotic transmission. We report a previously unknown poxvirus infection in 2 patients, 1 of whom was immunocompromised; both patients had known equine contact.

METHODS

The patients were interviewed and clinical information was abstracted from the patients' medical files. Biopsies of the skin lesions were collected from both patients for histopathology, immunohistochemistry, and transmission electron microscopy analysis. Oral and skin swabs were collected from animals with frequent contact with the patients, and environmental sampling including rodent trapping was performed on the farm where the immunosuppressed patient was employed. "Pan-pox and high Guanine-cytosine" polymerase chain reaction assays were performed on patient, animal, and environmental isolates. Amplicon sequences of the viral DNA were used for agent identification and phylogenetic analysis.

RESULTS

Specimens from both human cases revealed a novel poxvirus. The agent shares 88% similarity to viruses in the Parapoxvirus genus and 78% to those in the Molluscipoxvirus genus but is sufficiently divergent to resist classification as either. All animal and environmental specimens were negative for poxvirus and both patients had complete resolution of lesions.

CONCLUSIONS

This report serves as a reminder that poxviruses should be considered in cutaneous human infections, especially in individuals with known barnyard exposures. The clinical course of the patients was similar to that of parapoxvirus infections, and the source of this virus is currently unknown but is presumed to be zoonotic. This report also demonstrates the importance of a comprehensive approach to diagnosis of human infections caused by previously unknown pathogens.

Zoonotic parapoxviruses detected in symptomatic cattle in Bangladesh

Background

Application of molecular diagnostic methods to the determination of etiology in suspected poxvirus-associated infections of bovines is important both for the diagnosis of the individual case and to form a more complete understanding of patterns of strain occurrence and spread. The objective of this study was to identify and characterize bovine-associated zoonotic poxviruses in Bangladesh which are relevant to animal and human health.

Findings

Investigators from the International Center Diarrhoeal Disease Research (icddr,b), the US Centers for Disease Control and Prevention (CDC), and the Bangladesh Department of Livestock Services traveled to three districts in Bangladesh—Siranjganj, Rangpur and Bhola–to collect diagnostic specimens from dairy cattle and buffalo that had symptoms consistent with poxvirus-associated infections. Bovine papular stomatitis virus (BPSV) DNA was obtained from lesion material (teat) and an oral swab collected from an adult cow and calf (respectively) from a dairy production farm in Siranjganj. Pseudocowpox virus (PCPV) DNA signatures were obtained from a scab and oral swab collected from a second dairy cow and her calf from Rangpur.

Conclusions

We report the first detection of zoonotic poxviruses from Bangladesh and show phylogenetic comparisons between the Bangladesh viruses and reference strains based on analyses of the B2L and J6R loci (vaccinia orthologs). Understanding the range and diversity of different species and strains of parapoxvirus will help to spotlight unusual patterns of occurrence that could signal events of significance to the agricultural and public health sectors.

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.

An Investigation of a Cluster of Parapoxvirus Cases in Missouri, Feb-May 2006: Epidemiologic, Clinical and Molecular Aspects

In the spring of 2006, four human cases of parapoxvirus infections in Missouri residents were reported to the Centers for Disease Control and Prevention (CDC), two of which were initially diagnosed as cutaneous anthrax. This investigation was conducted to determine the level of recognition of zoonotic parapoxvirus infections and prevention measures, the degree to which veterinarians may be consulted on human infections and what forces were behind this perceived increase in reported infections. Interviews were conducted and clinical and environmental sampling was performed. Swab and scab specimens were analyzed by real-time polymerase chain reaction (PCR), whereas serum specimens were evaluated for parapoxvirus antibodies. Three case patients were found to have fed ill juvenile animals without using gloves. Forty-six percent of veterinarians reported having been consulted regarding suspected human orf infections. Orf virus DNA was detected from five of 25 asymptomatic sheep. Analysis of extracellular envelope gene sequences indicated that sheep and goat isolates clustered in a species-preferential fashion. Parapoxvirus infections are common in Missouri ruminants and their handlers. Infected persons often do not seek medical care; some may seek advice from veterinarians rather than physicians. The initial perception of increased incidence in Missouri may have arisen from a reporting artifact stemming from heightened concern about anthrax. Asymptomatic parapoxvirus infections in livestock may be common and further investigation warranted.

Bovine papular stomatitis affecting dairy cows and milkers in midwestern Brazil

Bovine papular stomatitis virus (BPSV) is a parapoxvirus associated with papular and erosive lesions on the muzzle, lips, and oral mucosa of cattle. Teats of milking cows are occasionally affected, and the infection is frequently transmitted to human beings. The present report describes an outbreak of BPSV infection affecting cows in midwestern Brazil, with human involvement. The disease was observed in neighboring small hand-milking farms, affecting 20 milking cows. The signs included painful reddish papules, ulcers, and scabby proliferative lesions on the teats, with a clinical course of 7-12 days. Affected cows presented severe local pain, not allowing the completion of milking. Histologically, acanthosis, spongiosis, and parakeratotic hyperkeratosis with adjacent focally extensive ulcers and multifocal inflammatory infiltrate were observed in the epidermis. Eosinophilic inclusion bodies were noted in the cytoplasm of epithelial cells. Personnel milking the affected cows developed lesions on the hands, painful papules that progressed to ulcerative and scabby lesions in 4-7 days. A polymerase chain reaction using a set of pan-parapoxvirus primers for the B2L gene performed on DNA extracted from scabs amplified a 590-bp product, which when sequenced, revealed similarities of 99%, 85%, and 84% with BPSV, Pseudocowpox virus, and Orf virus, respectively. A phylogenetic tree based on the B2L sequence was constructed, showing that the virus clustered with BPSV isolates. Although clinical cases compatible with BSPV infection have been frequently described in Brazil, the present report identifies the agent associated with cattle and human disease in the country.

An outbreak of pseudocowpox in fattening calves in southern Brazil

Pseudocowpox virus is a parapoxvirus frequently associated with papulovesicular and scabby lesions on the teats and udders of milking cows and is often transmitted to human beings. An unusual outbreak of skin disease in fattening calves in southern Brazil is described. Fourteen of 17 male cattle (82%), aged 6-48 months, feeding on grass pastures were affected. Animals developed papules, vesicles, and scabby proliferative lesions on the muzzle in a clinical course of approximately 10-15 days. The scabby lesions often presented with exudation and bleeding. Histological examination of mucocutaneous tissue in detached scabs revealed acanthosis with thickening of the corneal layer and premature keratinization (parakeratotic hyperkeratosis). The dermis had multifocal lymphoplasmacytic infiltrates. Electron microscopic examination of scab specimens revealed typical parapoxvirus particles: oval shaped (260 nm × 160 nm), enveloped, and covered with a helical layer. Polymerase chain reaction using a set of pan-parapoxvirus primers for the B2L gene amplified a 590-bp product out of DNA extracted from scabs. Nucleotide sequencing of the amplicons revealed a nucleotide homology of 97% with Pseudocowpox virus and lower homology with other parapoxviruses: Bovine papular stomatitis virus (84%) and Orf virus (94%). A phylogenetic tree based on the B2L sequence was constructed, showing that the virus clustered with Pseudocowpox virus isolates.

Zoonotic Poxviruses Associated with Companion Animals

Simple Summary

Contemporary enthusiasm for the ownership of exotic animals and hobby livestock has created an opportunity for the movement of poxviruses—such as monkeypox, cowpox, and orf—outside their traditional geographic range bringing them into contact with atypical animal hosts and groups of people not normally considered at risk. It is important that pet owners and practitioners of human and animal medicine develop a heightened awareness for poxvirus infections and understand the risks that can be associated with companion animals and livestock. This article reviews the epidemiology and clinical features of zoonotic poxviruses that are most likely to affect companion animals.

Abstract

Understanding the zoonotic risk posed by poxviruses in companion animals is important for protecting both human and animal health. The outbreak of monkeypox in the United States, as well as current reports of cowpox in Europe, point to the fact that companion animals are increasingly serving as sources of poxvirus transmission to people. In addition, the trend among hobbyists to keep livestock (such as goats) in urban and semi-urban areas has contributed to increased parapoxvirus exposures among people not traditionally considered at high risk. Despite the historic notoriety of poxviruses and the diseases they cause, poxvirus infections are often missed. Delays in diagnosing poxvirus-associated infections in companion animals can lead to inadvertent human exposures. Delays in confirming human infections can result in inappropriate treatment or prolonged recovery. Early recognition of poxvirus-associated infections and application of appropriate preventive measures can reduce the spread of virus between companion animals and their owners. This review will discuss the epidemiology and clinical features associated with the zoonotic poxvirus infections most commonly associated with companion animals.

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.

Orthopoxvirus genome evolution: the role of gene loss

Poxviruses are highly successful pathogens, known to infect a variety of hosts. The family Poxviridae includes Variola virus, the causative agent of smallpox, which has been eradicated as a public health threat but could potentially reemerge as a bioterrorist threat. The risk scenario includes other animal poxviruses and genetically engineered manipulations of poxviruses. Studies of orthologous gene sets have established the evolutionary relationships of members within the Poxviridae family. It is not clear, however, how variations between family members arose in the past, an important issue in understanding how these viruses may vary and possibly produce future threats. Using a newly developed poxvirus-specific tool, we predicted accurate gene sets for viruses with completely sequenced genomes in the genus Orthopoxvirus. Employing sensitive sequence comparison techniques together with comparison of syntenic gene maps, we established the relationships between all viral gene sets. These techniques allowed us to unambiguously identify the gene loss/gain events that have occurred over the course of orthopoxvirus evolution. It is clear that for all existing Orthopoxvirus species, no individual species has acquired protein-coding genes unique to that species. All existing species contain genes that are all present in members of the species Cowpox virus and that cowpox virus strains contain every gene present in any other orthopoxvirus strain. These results support a theory of reductive evolution in which the reduction in size of the core gene set of a putative ancestral virus played a critical role in speciation and confining any newly emerging virus species to a particular environmental (host or tissue) niche.