Isolation and Characterization of Akhmeta Virus from Wild-Caught Rodents (Apodemus spp.) in Georgia.

In 2013, a novel orthopoxvirus was detected in skin lesions of two cattle herders from the Kakheti region of Georgia (country); this virus was named Akhmeta virus. Subsequent investigation of these cases revealed that small mammals in the area had serological evidence of orthopoxvirus infections, suggesting their involvement in the maintenance of these viruses in nature. In October 2015, we began a longitudinal study assessing the natural history of orthopoxviruses in Georgia. As part of this effort, we trapped small mammals near Akhmeta (n = 176) and Gudauri (n = 110). Here, we describe the isolation and molecular characterization of Akhmeta virus from lesion material and pooled heart and lung samples collected from five wood mice (Apodemus uralensis and Apodemus flavicollis) in these two locations. The genomes of Akhmeta virus obtained from rodents group into 2 clades: one clade represented by viruses isolated from A. uralensis samples, and one clade represented by viruses isolated from A. flavicollis samples. These genomes also display several presumptive recombination events for which gene truncation and identity have been examined.IMPORTANCE Akhmeta virus is a unique Orthopoxvirus that was described in 2013 from the country of Georgia. This paper presents the first isolation of this virus from small mammal (Rodentia; Apodemus spp.) samples and the molecular characterization of those isolates. The identification of the virus in small mammals is an essential component to understanding the natural history of this virus and its transmission to human populations and could guide public health interventions in Georgia. Akhmeta virus genomes harbor evidence suggestive of recombination with a variety of other orthopoxviruses; this has implications for the evolution of orthopoxviruses, their ability to infect mammalian hosts, and their ability to adapt to novel host species.

[Human poxvirus infections]. / Infections humaines à poxvirus.

Poxvirus (PXV) infections are a common cause of cutaneous signs. In France, certain forms of poxvirus are frequent and benign (molluscum contagiosum), while others are rare but potentially serious (cowpox virus [CPXV]). Whereas only smallpox and molluscum contagiosum viruses have a human reservoir and are transmitted between humans, most poxvirus infections are zoonoses having only animal reservoirs. Only a small number of poxviruses are responsible for infection in humans, but the increasing number of new pets, some of which are exotic, coupled with the rapid rise in international travel are creating a greater risk of transmission of zoonotic PXV to new vectors and of spread of these diseases to new regions throughout the world. In France, molluscum contagiosum, orf and milkers' nodule give rise to numerous consultations and are well known to dermatologists. However, dermatologists must also be able to identify other parapoxviruses of similar presentation to orf; thus, CPXV and monkeypox are considered potentially emergent viruses with a high risk of epidemic and spread due to increasing international transport and the loss of the maximum protection against smallpox. Finally, despite its declared eradication, smallpox is currently being monitored because of the potential risk of reintroduction, whether accidentally or deliberately through bioterrorism.

Bayesian Phylogenetic Analysis of Avipoxviruses from North American Wild Birds Demonstrates New Insights into Host Specificity and Interspecies Transmission.

Avian pox is commonly diagnosed in a variety of North American wild and domestic birds, yet little is known about the evolutionary relationships among the causative poxviruses. This study aimed to determine the phylogenetic relationships among isolates identified in different avian host species to better characterize the host range of specific viral strains and compare the genetic variability within and between viral clades. Skin lesions grossly and microscopically consistent with poxvirus infection from 82 birds collected in Canada, the United States, and the U.S. Virgin Islands were included in this study. A total of 12 avian species were represented; the most common species sampled were wild turkeys (Meleagris gallopavo), mourning doves (Zenaida macroura), and American crows (Corvus brachyrhynchos). Poxvirus samples from these birds were genotyped using PCR that targeted the 4b core protein gene followed by amplicon sequencing. Bayesian phylogenetic analyses of these viruses, in conjunction with publicly available sequences, representing avipoxvirus strains from six continents revealed statistically significant monophyletic clades based on genetic distances of sequences within and between observed clades. Genetic variation within the fowlpox clade was low compared to the canarypox clade. Host and geographic origins of viral isolates revealed overall clustering of viral strains within avian species, with a few exceptions. No genetic differences were observed between viruses from Canada and the United States within individual species. These results are novel in their characterization and comparison of the phylogenetic relationships of poxvirus isolates in wild bird species from North America. Further, we provide new data on the level of host specificity and specific strains circulating in North America.

El análisis filogenético bayesiano de los avipoxvirus de las aves silvestres de América del Norte demuestra nuevos conocimientos sobre la especificidad del huésped y la transmisión interespecífica. La viruela aviar se diagnostica comúnmente en una variedad de aves silvestres y domésticas de América del Norte, pero se sabe poco sobre las relaciones evolutivas entre los poxvirus. Este estudio tuvo como objetivo determinar las relaciones filogenéticas entre aislamientos identificados en diferentes especies de hospedadores aviares para caracterizar mejor el rango de hospedadores de cepas virales específicas y comparar la variabilidad genética dentro y entre los clados virales. Se incluyeron en este estudio lesiones cutáneas que eran consistentes macro y microscópicamente con la infección por poxvirus de 82 aves recolectadas en Canadá, Estados Unidos y las Islas Vírgenes de los Estados Unidos. Un total de 12 especies de aves fueron representadas; las especies más comunes en la muestra fueron los pavos silvestres (Meleagris gallopavo), huilota común (Zenaida macroura) y cuervos americanos (Corvus brachyrhynchos). Las muestras de poxvirus de estas aves fueron genotipadas mediante PCR que se enfocó en el gene de la proteína central 4b seguido de secuenciación de amplicón. Los análisis filogenéticos bayesianos de estos virus, junto con las secuencias disponibles públicamente, que representan cepas de avipoxvirus de seis continentes revelaron clados monofiléticos estadísticamente significativos basados en distancias genéticas de las secuencias dentro y entre los clados observados. La variación genética dentro del clado de la viruela del pollo fue baja en comparación con el clado de virus de canario. El huésped y los orígenes geográficos de los aislamientos virales revelaron un agrupamiento general de cepas virales dentro de las especies aviares, con algunas excepciones. No se observaron diferencias genéticas entre los virus de Canadá y los Estados Unidos dentro de las especies individuales. Estos resultados son novedosos en la caracterización y comparación de las relaciones filogenéticas de los aislados de poxvirus en especies de aves silvestres de América del Norte. Además, se proporcionan nuevos datos sobre el nivel de especificidad del huésped y las cepas específicas que circulan en América del Norte. Key words: Bayesian analysis, mourning dove, phylogenetic, poxvirus, sequencing, wild turkey, 4b gene.

Two cases of monkeypox imported to the United Kingdom, September 2018.

In early September 2018, two cases of monkeypox were reported in the United Kingdom (UK), diagnosed on 7 September in Cornwall (South West England) and 11 September in Blackpool (North West England). The cases were epidemiologically unconnected and had recently travelled to the UK from Nigeria, where monkeypox is currently circulating. We describe the epidemiology and the public health response for the first diagnosed cases outside the African continent since 2003.

Health hazards to wild birds and risk factors associated with anthropogenic food provisioning.

Provision of supplementary food for wild birds at garden feeding stations is a common, large-scale and year-round practice in multiple countries including Great Britain (GB). While these additional dietary resources can benefit wildlife, there is a concomitant risk of disease transmission, particularly when birds repeatedly congregate in the same place at high densities and through interactions of species that would not normally associate in close proximity. Citizen science schemes recording garden birds are popular and can integrate disease surveillance with population monitoring, offering a unique opportunity to explore inter-relationships between supplementary feeding, disease epidemiology and population dynamics. Here, we present findings from a national surveillance programme in GB and note the dynamism of endemic and emerging diseases over a 25-year period, focusing on protozoal (finch trichomonosis), viral (Paridae pox) and bacterial (passerine salmonellosis) diseases with contrasting modes of transmission. We also examine the occurrence of mycotoxin contamination of food residues in bird feeders, which present both a direct and indirect (though immunosuppression) risk to wild bird health. Our results inform evidence-based mitigation strategies to minimize anthropogenically mediated health hazards, while maintaining the benefits of providing supplementary food for wild birds.This article is part of the theme issue 'Anthropogenic resource subsidies and host-parasite dynamics in wildlife'.

A paralogous pair of mammalian host restriction factors form a critical host barrier against poxvirus infection.

Host restriction factors constitute a formidable barrier for viral replication to which many viruses have evolved counter-measures. Human SAMD9, a tumor suppressor and a restriction factor for poxviruses in cell lines, is antagonized by two classes of poxvirus proteins, represented by vaccinia virus (VACV) K1 and C7. A paralog of SAMD9, SAMD9L, is also encoded by some mammals, while only one of two paralogs is retained by others. Here, we show that SAMD9L functions similarly to SAMD9 as a restriction factor and that the two paralogs form a critical host barrier that poxviruses must overcome to establish infection. In mice, which naturally lack SAMD9, overcoming SAMD9L restriction with viral inhibitors is essential for poxvirus replication and pathogenesis. While a VACV deleted of both K1 and C7 (vK1L-C7L-) was restricted by mouse cells and highly attenuated in mice, its replication and virulence were completely restored in SAMD9L-/- mice. In humans, both SAMD9 and SAMD9L are poxvirus restriction factors, although the latter requires interferon induction in many cell types. While knockout of SAMD9 with Crispr-Cas9 was sufficient for abolishing the restriction for vK1L-C7L- in many human cells, knockout of both paralogs was required for abolishing the restriction in interferon-treated cells. Both paralogs are antagonized by VACV K1, C7 and C7 homologs from diverse mammalian poxviruses, but mouse SAMD9L is resistant to the C7 homolog encoded by a group of poxviruses with a narrow host range in ruminants, indicating that host species-specific difference in SAMD9/SAMD9L genes serves as a barrier for cross-species poxvirus transmission.

Understanding orthopoxvirus host range and evolution: from the enigmatic to the usual suspects.

In general, orthopoxviruses can be considered as falling into one of three host-utilization categories: highly specialized, single-host; broad host range; or 'cryptic', the last encompassing those viruses about which very little is known. Single-host viruses tend to exploit abundant hosts that have consistent patterns of interaction. For these viruses, observed genome reduction and loss of presumptive host-range genes is thought to be a consequence of relaxed selection. In contrast, the large genome size retained among broad host range orthopoxviruses suggests these viruses may depend on multiple host species for persistence in nature. Our understanding of the ecologic requirements of orthopoxviruses is strongly influenced by geographic biases in data collection. This hinders our ability to predict potential sources for emergence of orthopoxvirus-associated infections.

Modeling the spread of capripoxvirus among livestock and optimal vaccination strategies.

Capripox is an important transboundary animal disease that is endemic across Africa, the Middle East, and some parts of Asia. The disease is highly contagious and considered to be a major obstacle causing significant economic loses in many agricultural areas. In this study, a mathematical model is developed to describe the transmission dynamics of capripoxvirus (CaPV) among livestock. This proposed model incorporates direct and indirect transmission of CaPV, together with two vaccination strategies, to investigate their effects on the severity of outbreaks and the prevalence of CaPV among the livestock population. The results suggest that ratio of potential vectors to livestock, successful probability of infection, vaccination rates, waning rate of vaccine-conferred protection, and virus introduction time play crucial roles in determining the outbreak severity and the prevalence level. The results also show that it is optimal to vaccinate newborns at the maximum effort throughout the control program and moderately increase vaccination rate for a susceptible pool to reach its maximum level after the outbreak.

Milker's nodule: an occupational infection and threat to the immunocompromised.

Milker's nodule virus, also called paravaccinia virus, is a DNA virus of the parapoxvirus genus transmitted from infected cows to humans. It results from contact with cattle, cattle by-products or fomites. Classified as an occupational disorder, those at risk of exposure include farmers, butchers and agricultural tourists. The viral infection begins 5-15 days after inoculation as an erythematous-purple, round nodule with a clear depressed centre and a surrounding erythematous ring. While familiar to those in farming communities, the presence of the nodule may be concerning to others, particularly the immunosuppressed. Milker's nodules are self-limited in immunocompetent individuals and heal without scarring within 8 weeks. Another member of the Parapoxvirus genus, the orf virus, is also transmitted from animals to humans by direct contact. While complications are rare, haematopoietic stem cell transplant recipients are at risk of graft-versus-host disease, as the parapoxvirus may trigger these complications in immunocompromised individuals. In addition, paravaccinia may serve as the antigen source for the development of erythema multiforme. The unique structure and replication process of viruses in the Poxvirus family, while includes the Parapoxvirus genus, have been a focus for treatment of infections and cancer. Manipulation of these viruses has demonstrated promising therapeutic possibilities as vectors for vaccines and oncologic therapy.

Dynamics of Pathological and Virological Findings During Experimental Calpox Virus Infection of Common Marmosets (Callithrix jacchus).

Experimental intranasal infection of marmosets (Callithrix jacchus) with calpox virus results in fatal disease. Route and dose used for viral inoculation of the test animals mimics the natural transmission of smallpox, thus representing a suitable model to study pathogenesis and to evaluate new vaccines against orthopoxvirus infection. However, the pathogenic mechanisms leading to death are still unclear. Therefore, our study aimed at investigating the kinetics of pathological alterations to clarify the pathogenesis in calpox virus infection. Following intranasal inoculation with two different viral doses, common marmosets were sacrificed on days 3, 5, 7, 10 and 12 post inoculation. Collected tissue was screened using histopathology, immunohistochemistry, transmission electron microscopy, and virological assays. Our data suggest that primary replication took place in nasal and bronchial epithelia followed by secondary replication in submandibular lymph nodes and spleen. Parallel to viremia at day 7, virus was detectable in many organs, mainly located in epithelial cells and macrophages, as well as in endothelial cells. Based on the onset of clinical signs, the histological and ultrastructural lesions and the immunohistochemical distribution pattern of the virus, the incubation period was defined to last 11 days, which resembles human smallpox. In conclusion, the data indicate that the calpox model is highly suitable for studying orthopoxvirus-induced disease.

Evaluation of Taterapox Virus in Small Animals.

Taterapox virus (TATV), which was isolated from an African gerbil (Tatera kempi) in 1975, is the most closely related virus to variola; however, only the original report has examined its virology. We have evaluated the tropism of TATV in vivo in small animals. We found that TATV does not infect Graphiurus kelleni, a species of African dormouse, but does induce seroconversion in the Mongolian gerbil (Meriones unguiculatus) and in mice; however, in wild-type mice and gerbils, the virus produces an unapparent infection. Following intranasal and footpad inoculations with 1 × 106 plaque forming units (PFU) of TATV, immunocompromised stat1-/- mice showed signs of disease but did not die; however, SCID mice were susceptible to intranasal and footpad infections with 100% mortality observed by Day 35 and Day 54, respectively. We show that death is unlikely to be a result of the virus mutating to have increased virulence and that SCID mice are capable of transmitting TATV to C57BL/6 and C57BL/6 stat1-/- animals; however, transmission did not occur from TATV inoculated wild-type or stat1-/- mice. Comparisons with ectromelia (the etiological agent of mousepox) suggest that TATV behaves differently both at the site of inoculation and in the immune response that it triggers.

Identification of Clade E Avipoxvirus, Mozambique, 2016.

Analysis of scab samples collected from poultry during outbreaks of fowlpox in Mozambique in 2016 revealed the presence of clade E avipoxviruses. Infected poultry were from flocks that had been vaccinated against fowlpox virus. These findings require urgent reevaluation of the vaccine formula and control strategies in this country.

MOLECULAR EPIDEMIOLOGY OF AVIAN POXVIRUS IN THE ORIENTAL TURTLE DOVE (STREPTOPELIA ORIENTALIS) AND THE BITING MIDGE (CULICOIDES ARAKAWAE) IN THE REPUBLIC OF KOREA.

A total of 600 wild birds were analyzed for the causes of mortality in the Republic of Korea (ROK) from 2011 to 2013. Avian poxvirus (APV) infections were identified as the primary cause of mortality in 39% (29/74) Oriental Turtle Doves (Streptopelia orientalis). At necropsy, all 29 S. orientalis birds, of which, 76% (22/29) were juveniles, had severe diphtheritic lesions in their oral and nasal cavities and on their eyelids, which were the lesions of APV that resulted in mortality. We detected APV infection by chorioallantoic membrane inoculation and molecular study of the partial region of the P4b gene. All isolates belonged to the same APV strain and were identical to strains isolated from several different pigeon species in South Africa. Phylogenetically, the APV strain identified in S. orientalis belonged to subclade A2, which includes isolates from several species of pigeons from different parts of the world, including the United Kingdom, Germany, India, Egypt, Hawaii, Georgia, Hungary, South Africa, Tanzania, and the ROK. This identity indicated that this diphtheritic APV strain may be a potential pathogen of other pigeon species in the ROK and neighboring countries throughout the range of S. orientalis. However, reticuloendotheliosis virus insertion into the APV genome was not detected by PCR in any of the 29 APV infections. An identical strain of APV observed in S. orientalis was also detected in Culicoides arakawae (biting midge), with annual peak populations corresponding to the presence of APV in S. orientalis. Culicoides arakawae may be a primary vector of APV in S. orientalis. Active surveillance of APVs in wild birds and C. arakawae is needed to better understand the epidemiology of APVs, host-vector relationships, and its ecological effects on S. orientalis in the ROK.

Ca. Branchiomonas cysticola, Ca. Piscichlamydia salmonis and Salmon Gill Pox Virus transmit horizontally in Atlantic salmon held in fresh water.

Elucidation of the role of infectious agents putatively involved in gill disease is commonly hampered by the lack of culture systems for these organisms. In this study, a farmed population of Atlantic salmon pre-smolts, displaying proliferative gill disease with associated Candidatus Branchiomonas cysticola, Ca. Piscichlamydia salmonis and Atlantic salmon gill pox virus (SGPV) infections, was identified. A subpopulation of the diseased fish was used as a source of waterborne infection towards a population of naïve Atlantic salmon pre-smolts. Ca. B. cysticola infection became established in exposed naïve fish at high prevalence within the first month of exposure and the bacterial load increased over the study period. Ca. P. salmonis and SGPV infections were identified only at low prevalence in exposed fish during the trial. Although clinically healthy, at termination of the trial the exposed, naïve fish displayed histologically visible pathological changes typified by epithelial hyperplasia and subepithelial inflammation with associated bacterial inclusions, confirmed by fluorescent in situ hybridization to contain Ca. B. cysticola. The results strongly suggest that Ca. B. cysticola infections transmit directly from fish to fish and that the bacterium is directly associated with the pathological changes observed in the exposed, previously naïve fish.

Human and Dromedary Camel Infection with Camelpox Virus in Eastern Sudan.

We provide evidence for the zoonotic nature of camelpox virus by reporting infections that involved dromedary camels and three camel herders in Showak area of eastern Sudan between September and December 2014. The skin lesions in the camel herders consisted of erythema, vesicles, and pustules that involved arms, hands, legs, back, and abdomen and resolved within less than 2 months with no human-to-human transmission. The diagnosis was achieved through molecular technique, virus isolation in cell culture, and partial genome sequencing.

Camelpox: A brief review on its epidemiology, current status and challenges.

Camelpox caused by a Camelpox virus (CMLV) is a very important host specific viral disease of camel. It is highly contagious in nature and causes serious impact on health even mortality of camels and economic losses to the camel owners. It manifests itself either in the local/mild or generalized/severe form. Various outbreaks of different pathogenicity have been reported from camel dwelling areas of the world. CMLV has been characterized in embryonated chicken eggs with the production of characteristic pock lesions and in various cell lines with the capacity to induce giant cells. Being of Poxviridae family, CMLV employs various strategies to impede host immune system and facilitates its own pathogenesis. Both live and attenuated vaccine has been found effective against CMLV infection. The present review gives a comprehensive overview of camelpox disease with respect to its transmission, epidemiology, virion characteristics, viral life cycle, host interaction and its immune modulation.

Detection and characterization of atypical capripoxviruses among small ruminants in India.

Recent developments in molecular biology shed light on cross-species transmission of SPPV and GTPV. The present study was planned to characterize the capripoxviruses which were circulating in the field condition among sheep and goats using RPO30 gene-based viral lineage (SPPV/GTPV) differentiating PCR and sequencing of RPO30 and GPCR genes from clinical samples. Out of 58 scabs (35 sheep and 23 goats) screened, 27 sheep and 18 goat scabs were found positive for capripox virus infections. With the exception of one sheep and one goat scabs, all the positive samples yielded amplicon size according to host origin, i.e. SPPV in sheep and GTPV in goats. In the above two exceptional cases, goat scab and sheep scab yielded amplicon size as that of SPPV and GTPV, respectively. Further, sequencing and phylogenetic analyses of complete ORFs of RPO30 and GPCR genes from six sheep and three goat scabs revealed that with the exception of above two samples, all had host-specific signatures and clustered according to their host origin. In case of cross-species infecting samples, sheep scab possessed GTPV-like signatures and goat scab possessed SPPV-like signatures. Our study identifies the circulation of cross-infecting SPPV and GTPV in the field and warrants the development of single-strain vaccine which can protect the animals from both sheeppox and goatpox diseases.

Human infection with a zoonotic orthopoxvirus in the country of Georgia.

During 2013, cutaneous lesions developed in two men in the country of Georgia after they were exposed to ill cows. The men had never received vaccination against smallpox. Tests of lesion material with the use of a quantitative real-time polymerase-chain-reaction assay for non-variola virus orthopoxviruses were positive, and DNA sequence analysis implicated a novel orthopoxvirus species. During the ensuing epidemiologic investigation, no additional human cases were identified. However, serologic evidence of exposure to an orthopoxvirus was detected in cows in the patients' herd and in captured rodents and shrews. A third case of human infection that occurred in 2010 was diagnosed retrospectively during testing of archived specimens that were originally submitted for tests to detect anthrax. Orthopoxvirus infection should be considered in persons in whom cutaneous lesions develop after contact with animals.