Cowpox in zoo and wild animals in the United Kingdom.

Cowpox virus is considered to be a re-emerging zoonotic pathogen and a public health threat due to increasing numbers of cases in humans and animals in Europe over the past decade, including within the United Kingdom (UK). We present epidemiological data and diagnostic features of 27 recent, naturally occurring cowpox cases in zoo and wild animals across the UK, including the first reports of cowpox in two snow leopards (Panthera uncia), a Bengal tiger (Panthera tigris tigris), three Chilean pudus (Pudu puda), a Malayan tapir (Tapirus indicus) and a Eurasian otter (Lutra lutra), and the first reports of Orthopoxvirus infection in a lar gibbon (Hylobates lar), a Southern tamandua (Tamandua tetradactyla) and an aardvark (Orycteropus afer). This study provides a detailed overview of cowpox infections in a wide range of non-domestic animal species, presents a range of methods for diagnosis and demonstrates the value of retrospective analysis of pathology surveillance in revealing epidemiological links.

A Belgian student with black eschars.

BACKGROUND: Human cowpox virus infection is a rare zoonotic disease. Cowpox virus is a member of the Orthopoxvirus genus, like smallpox. Over the last years records of cowpox virus transmission from pet cats and pet rats to humans in Europe have increased. This observation may result from the loss of cross-immunity against orthopoxviruses after discontinuation of routine smallpox vaccination in the 1980s. CASE PRESENTATION: We report the first case of a human cowpox infection in an unvaccinated Belgian citizen. This 19-year-old student presented with multiple necrotic skin lesions on the chin, the scalp and the pubic region, and with cervical lymphadenopathy and flu-like symptoms. The diagnosis of human cowpox was based on electron microscopic findings and PCR examination performed on a skin biopsy of the pubic lesion. Close contact with cats (her domestic cats or cats from a local shelter) was probably the source of transmission. Spreading of the lesions was likely the result of autoinoculation. After six months all lesions spontaneously healed with atrophic scars. DISCUSSION: To enhance awareness of this rare viral zoonosis and to verify the suspected increase in incidence and symptom severity after cessation of smallpox vaccination, one could argue whether human cowpox should become a notifiable disease.

Genomic Sequencing and Phylogenomics of Cowpox Virus.

Cowpox virus (CPXV; genus Orthopoxvirus; family Poxviridae) is the causative agent of cowpox, a self-limiting zoonotic infection. CPXV is endemic in Eurasia, and human CPXV infections are associated with exposure to infected animals. In the Fennoscandian region, five CPXVs isolated from cats and humans were collected and used in this study. We report the complete sequence of their genomes, which ranged in size from 220-222 kbp, containing between 215 and 219 open reading frames. The phylogenetic analysis of 87 orthopoxvirus strains, including the Fennoscandian CPXV isolates, confirmed the division of CPXV strains into at least five distinct major clusters (CPXV-like 1, CPXV-like 2, VACV-like, VARV-like and ECTV-Abatino-like) and can be further divided into eighteen sub-species based on the genetic and patristic distances. Bayesian time-scaled evolutionary history of CPXV was reconstructed employing concatenated 62 non-recombinant conserved genes of 55 CPXV. The CPXV evolution rate was calculated to be 1.65 × 10-5 substitution/site/year. Our findings confirmed that CPXV is not a single species but a polyphyletic assemblage of several species and thus, a reclassification is warranted.

Fatal Cowpox Virus Infection in Human Fetus, France, 2017.

Cowpox virus (CPXV) has an animal reservoir and is typically transmitted to humans by contact with infected animals. In 2017, CPXV infection of a pregnant woman in France led to the death of her fetus. Fetal death after maternal orthopoxvirus (smallpox) vaccination has been reported; however, this patient had not been vaccinated. Investigation of the patient's domestic animals failed to demonstrate prevalence of CPXV infection among them. The patient's diagnosis was confirmed by identifying CPXV DNA in all fetal and maternal biopsy samples and infectious CPXV in biopsy but not plasma samples. This case of fetal death highlights the risk for complications of orthopoxvirus infection during pregnancy. Among orthopoxviruses, fetal infection has been reported for variola virus and vaccinia virus; our findings suggest that CPXV poses the same threats for infection complications as vaccinia virus.

Patchy Occurrence of Cowpox Virus in Voles from Germany.

Cowpox virus (CPXV), genus Orthopoxvirus, family Poxviridae, is a zoonotic pathogen in Eurasian wild rodents. High seroprevalences have been reported previously for vole and murine species in Europe. In contrast, viral DNA was only rarely detected, and very few reservoir-derived CPXV isolates exist. In this study, CPXV DNA and CPXV-reactive antibodies were monitored in wild small mammals for 5 years in four German federal states. Screening of liver tissues of 3966 animals by CPXV real-time PCR (qPCR) revealed five voles of two species positive for CPXV DNA. Two positive bank voles (Myodes glareolus) and two positive common voles (Microtus arvalis) originated from two plots in Baden-Wuerttemberg. One positive bank vole originated from Mecklenburg-Western Pomerania. None of the small mammals from Thuringia and North Rhine-Westphalia was positive in the qPCR. CPXV antigen-based indirect immunofluorescence assays of 654 highly diluted chest cavity fluid samples detected two bank voles and two common voles from the same sites in Baden-Wuerttemberg to be highly seroreactive. Five animals were CPXV DNA positive, and four other animals were orthopoxvirus seropositive. Our study indicates both a very low prevalence and a patchy occurrence of CPXV in common and bank voles and absence in other rodent and shrew species in Germany. The multiple detection of infected voles at one site in Baden-Wuerttemberg and continued detection in a region of Mecklenburg-Western Pomerania classify these regions as potential endemic foci.

Field Trial Vaccination against Cowpox in Two Alpaca Herds.

In Europe, cowpox virus (CPXV) infection in South American camelids occurs as a so-called spill-over infection. Although infected animals generally have a mild form of the disease and survive, cases of fatal generalised CPXV infection have also been described. Prevention by prophylactic vaccination is the only way to protect animals from disease. In the present study, modified vaccinia virus Ankara (MVA) vaccine, which has been successfully used in many animal species, was used in a prime-boost vaccination regimen in two alpaca herds with a history of CPXV infection. The focus of the study was the prevention of further clinical cases, and to determine the safety and immunogenicity of the MVA vaccine in alpacas. The MVA vaccine was well tolerated and safe in the 94 animals vaccinated. An indirect immunofluorescence assay (IFA) using MVA as an antigen showed that the seroprevalence of antibody after booster vaccination was 81.3% in herd I and 91.7% in herd II. Detectable antibody titres declined to 15.6% in herd I and 45.8% in herd II over a 12-month period after booster vaccination. Animals could be divided into four groups based on individual antibody titres determined over one year: Group 1 consisted of 19.3% of animals that were seropositive until the end of the trial period; Group 2 consisted of 58.0% of animals that were seropositive after booster vaccination, but seronegative one year later; Group 3 consisted of 14.7% of animals that were not seropositive at any time point; and Group 4 consisted of 7.9% of animals that were seropositive after initial immunisation, seronegative six months later, but seropositive or intermediate in IFA one year after immunisation, likely because of natural exposure. In new-born crias born to MVA-vaccinated mares, specific maternal antibodies were detected in 50.0% of animals up to 14 weeks of age. Our results confirm that MVA vaccination is a feasible tool for the prevention of CPXV disease in alpacas. Long-term studies are needed to verify future vaccination regimen in CPXV affected herds.

Molecular Detection and Characterization of the First Cowpox Virus Isolate Derived from a Bank Vole.

Cowpox virus (CPXV) is a zoonotic orthopoxvirus (OPV) that infects a wide range of mammals. CPXV-specific DNA and antibodies were detected in different vole species, such as common voles (Microtus arvalis) and bank voles (Myodes glareolus). Therefore, voles are the putative main reservoir host of CPXV. However, CPXV was up to now only isolated from common voles. Here we report the detection and isolation of a bank vole-derived CPXV strain (GerMygEK 938/17) resulting from a large-scale screening of bank voles collected in Thuringia, Germany, during 2017 and 2018. Phylogenetic analysis using the complete viral genome sequence indicated a high similarity of the novel strain to CPXV clade 3 and to OPV "Abatino" but also to Ectromeliavirus (ECTV) strains. Phenotypic characterization of CPXV GerMygEK 938/17 using inoculation of embryonated chicken eggs displayed hemorrhagic pock lesions on the chorioallantoic membrane that are typical for CPXV but not for ECTV. CPXV GerMygEK 938/17 replicated in vole-derived kidney cell lines but at lower level than on Vero76 cell line. In conclusion, the first bank vole-derived CPXV isolate provides new insights into the genetic variability of CPXV in the putative reservoir host and is a valuable tool for further studies about CPXV-host interaction and molecular evolution of OPV.

[Clinical presentation of cowpox virus infection in South American camelids - A review]. / Klinisches Erscheinungsbild der Kuhpockenvirus-infektion bei Neuweltkameliden.

Cowpox virus (CPXV) infection is a reportable and potentially zoonotic disease that occurs sporadically in a variety of animals. During the past six decades, CPXV infection has been extensively researched and described in both domestic (cat, dog, horse, cattle) and zoo animals (e. g. elephant, rhinoceros, okapi). Of note, a review of the literature produced only three reports of CPXV in individual or small groups of South American camelids. The goal of this review was to describe the current knowledge as it relates to clinical features of CPXV infection in South American camelids and to compare the clinical manifestations with those described in other animal species. In alpacas and llamas, virus transmission occurs via direct contact with infected animals or oronasal infection through microlesions in the skin and mucous membranes. In its mild form, the disease is limited to certain regions of the body (head, neck, extremities or perineal region) and characterised by pustules or crusts. CPXV infection can also cause generalised and frequently lethal disease with multifocal to diffuse skin lesions (papules, pustules, crusts, ulcers) accompanied by virus replication in other organs. Conjunctivitis, stomatitis and rhinitis are seen commonly together with nonspecific clinical signs, including anorexia, listlessness and fever. As in other poxvirus infections, factors leading to an immunosuppression may contribute to the development of the clinical ma -nifestation of CPXV infection. There appear to be no specific manifestations of CPXV infection in South American camelids. More research is needed to fully understand the pathogenesis and epidemio logy of CPXV infection, particularly in South American camelids.

Atypical Cowpox Virus Infection in a Series of Cats.

Within 4 weeks, five cats with skin lesions affecting the hindlimbs and mainly consisting of oedema, hyperaemia and plaque-like alterations were presented to the same veterinary clinic. The cats were suffering from lameness, trauma, renal insufficiency or complicated tail amputation. Although the lesions seemed unusual for a poxvirus infection, microscopical examination of biopsy samples or specimens taken during necropsy examination revealed ballooning degeneration of keratinocytes with eosinophilic, cytoplasmic inclusion bodies indicative of an orthopoxvirus infection. Cowpox virus infection was verified using immunohistochemistry and virus isolation. Molecular analysis revealed identical haemagglutinin gene sequences in four cases and spatiotemporal circumstances in some cases pointed to hospital-acquired transmission. Unusual manifestations of feline cowpox may have an unexpected risk for human infection.

Seasonal recurrence of cowpox virus outbreaks in captive cheetahs (Acinonyx jubatus).

Cowpox virus infections in captive cheetahs (Acinonyx jubatus) with high morbidity and mortality have already been reported in the UK and Russia in the 1970s. However, most of the reported cases have been singular events. Here, we report a total of five cowpox virus outbreaks in cheetahs in the same safari park in Denmark between 2010 and 2014. Nine cheetahs showed varying severity of clinical disease; two of them died (22%). All episodes occurred between August and October of the respective year. No other carnivores kept at the same institution nor the keepers taking care of the animals were clinically affected. The clinical picture of cowpox was confirmed by extensive laboratory investigations including histopathological and molecular analyses as well as cell culture isolation of a cowpox virus. High anti-orthopoxvirus antibody titers were detected in all 9 diseased cheetahs compared to seven contact cheetahs without clinical signs and 13 cheetahs not in direct contact. Additionally, whole genome sequencing from one sample of each cluster with subsequent phylogenetic analysis showed that the viruses from different outbreaks have individual sequences but clearly form a clade distinct from other cowpox viruses. However, the intra-clade distances are still larger than those usually observed within clades of one event. These findings indicate multiple and separate introductions of cowpox virus, probably from wild rodent populations, where the virus keeps circulating naturally and is only sporadically introduced into the cheetahs. Sero-positivity of voles (Arvicola amphibious) caught in zoo grounds strengthens this hypothesis. As a consequence, recommendations are given for medical and physical management of diseased cheetahs, for hygienic measures as well as for pre-shipment isolation before cheetah export from zoo grounds.

Fatal Cowpox Virus Infection in an Aborted Foal.

The article describes the isolation of a cowpox virus (CPXV) isolate originating from a horse. The skin of a foal, aborted in the third trimester, displayed numerous cutaneous papules. The histological examination showed A-type inclusion bodies within the lesion, typical for CPXV infections. This suspicion was confirmed by real-time PCR where various organs were analyzed. From skin samples, virus isolation was successfully performed. Afterwards, the whole genome of this new isolate "CPXV Amadeus" was sequenced by next-generation technology. Phylogenetic analysis clearly showed that "CPXV Amadeus" belongs to the "CPXV-like 1" clade. To our opinion, the study provides important additional information on rare accidental CPXV infections. From the natural hosts, the voles, species such as rats, cats, or different zoo animals are occasionally infected, but until now only two horse cases are described. In addition, there are new insights toward congenital CPXV infections.

Pulmonary cowpox in cats: five cases.

CASE SERIES SUMMARY: This case series documents five cases of pneumonia (with pleural effusion in three cases) caused by cowpox virus (CPxV) in domestic cats. Predisposition to pneumonia may have resulted from mixed infections in two cases (feline herpesvirus and Bordetella bronchiseptica in one cat, and Mycoplasma species in the other). RELEVANCE AND NOVEL INFORMATION: As well as diagnostic confirmation by previously described methods of virus isolation from skin lesions, and demonstration of pox virions in skin samples using electron microscopy and inclusion bodies in histological preparations, this is the first report of diagnosis by virus isolation from bronchoalveolar lavage fluid or pleural fluid, and demonstration of inclusion bodies in cytological preparations. This is also the first series to report treatment with interferon omega (IFN-ω). Two cats survived, both of which had been treated with IFN-ω. As CPxV represents a serious zoonotic risk it is an important differential diagnosis of pneumonia in cats.

[Cowpox virus infection in an alpaca (Vicugna pacos) - clinical symptoms, laboratory diagnostic findings and pathological changes]. / Kuhpockenvirusinfektion bei einem Alpaka (Vicugna pacos) - klinische Symptomatik, Diagnostik und pathologische Befunde.

Orthopoxvirus infections appear to be rare in South American Camelids, because only a few cases have been reported in the literature. Based on a generalized infection with cowpox virus in an alpaca, the clinical symptoms, laboratory diagnostic findings and the pathological changes are described. The case history showed a long treatment because of chronic skin lesions. The main clinical symptom was miliary papules over the entire skin. Furthermore, a bilateral mucopurulent conjunctivitis occurred as well as excessive salivation due to a severe erosive-ulcerative stomatitis. Although the animal received intensive treatment, it died 8 days after admission to the clinic. During necropsy, an erosive-ulcerative laryngitis as well as a necrotising pneumonia and lymphadenitis were observed. Histopathological examination of representative organ samples led to the diagnosis of a suspected orthopoxvirus infection. Electron microscopy and quantitative polymerase chain reaction (qPCR) of tissue samples confirmed this diagnosis. The virus could be isolated in tissue culture and a PCR with subsequent nucleotide sequencing identified cowpox virus as the causative agent for this generalised infection.

Fatal cowpox virus infection in cotton-top tamarins (Saguinus oedipus) in Germany.

Cowpox virus (CPXV) was isolated from a fatal outbreak among cotton-top tamarins. Samples from healthy common marmosets in contact were also CPXV genome positive. The CPXV isolated from the cotton-top tamarins exhibited a unique hemagglutinin sequence. Pathogenicity investigations using a Wistar rat model characterized the isolate as low pathogenic.

Cowpox virus infection in cats: ABCD guidelines on prevention and management.

OVERVIEW: The misnomer 'cowpox' has historical roots: cats rather acquire the virus from small rodents. It has a wide host spectrum (including man) and causes skin lesions, predominantly on the head and paws. Progressive proliferative ulcerations in kittens and immunosuppressed cats may take a fatal course. Cat owners should be informed about the zoonotic risk.

Feline cowpoxvirus infections in Germany: clinical and epidemiological aspects.

Clinical and epidemiological aspects of cats with cowpox in Germany from the years 2004 to 2010 are described and discussed. Questionnaires were sent to veterinarians and owners of affected cats identified with the help of a number of pathology laboratories. Of 69 mailed questionnaires, 45 veterinary and 26 owner questionnaires were returned and a total of 46 feline poxcases were evaluated. The cases were distributed all over Germany although there was an accumulation of cases in specific geographic areas. The clinical and epidemiological observations match those of other studies. The majority of cats were outdoor cats, came from a rural environment and developed clinical signs in late summer or autumn. All cats showed skin lesions which were predominantly localized on the anterior part of the body, 61% of the cats showed other clinical signs in addition to the skin lesions. Approximately half of the cats lived in a multi-pet household, but in only one case clinical signs typical for cowpox were observed in another cat of the household. In two cases a cat-to-human transmission was assumed. In addition, to evaluate the prevalence of pox virus infections in outdoor cats in areas with previous reports of such infections, 92 apparently unaffected outdoor cats were tested for orthopoxvirus antibodies using an indirect immunofluorescence assay. Sixteen (17%) of the tested serum samples were seropositive against orthopoxvirus (titre between 1:20 and 1:40).This is a higher serum prevalence than in previously published studies from Germany. A possible explanation is selection of a population of outdoor cats from regions with previous known clinical cases.

[Cowpox: features of spread after cancellation of mandatory pox immunization].

Features of spread of cowpox in the contemporary conditions are examined. A decrease of population immunity to pox in the population of Russia caused by cancellation of pox immunization, hidden circulation of cowpox virus in various species of rodents, as well as lack of vigilance to pathogenic orthopoxviurses in healthcare workers were noted to create the real preconditions for the emergence of infection of humans caused by cowpox virus. Thereby presence of means of express laboratory diagnostics of cowpox and means of effective medical protection for the prevention of development of this disease in the population of Russia becomes an actual necessity.

Cowpox virus isolate virulent in humans shows attenuated phenotype in mice.

We have cultured Cowpox virus (CPXV) from skin lesion material of a human patient from Austria. Phylogenetic comparison of the HA-gene revealed a rather homogeneous cluster with other local isolates from recent years, the A36R-gene was mostly related to elephant derived strains from Germany. Despite causing disease in human, the isolate AT/Carinthia/788/07 surprisingly even at high titers showed a highly reduced virulence in BALB/c mice upon intranasal inoculation as compared to vaccinia virus. This contrasts earlier reports on other CPXV isolates. Using shotgun DNA sequencing several insertions and deletions were found in genes presumably involved in host range, immune regulation as well as established virulence factors. These preliminary data could be an indication that CPXV strains with proven pathogenicity for humans may have reduced virulence in mice and vice versa. Additionally strains with a reduced virulence may have an advantage in persisting in less dense rodent populations.