Lethal distemper in badgers (Meles meles) following epidemic in dogs and wolves

Molecular analysis of canine distemper virus H gene in the golden jackal (Canis aureus) population from Serbia

Canine distemper virus (CDV) is a highly contagious and often fatal disease affecting wild and domesticated carnivores. The virus is a single-stranded RNA virus from the genus Morbillivirus and the family Paramyxoviridae. While domestic dogs are the most common hosts, the virus poses a significant threat to endangered wildlife due to its broad host range. This study aimed to characterize the CDV Haemagglutinin (H) gene in golden jackals and explore the molecular evolution of the virus in an underrepresented host. A total of 88 brain samples from hunted golden jackals were tested for the presence of CDV viral nucleic acid, and the H gene of positive samples was amplified and sequenced using the Sanger method. Phylogenetic analysis, conducted using maximum likelihood methods, revealed that all Serbian sequences clustered within the Arctic lineage. Notably, the analysis identified a tyrosine (Y) at position 549 of the H protein, a mutation commonly associated with wildlife hosts, instead of the histidine (H) typically found in domestic strains. Additionally, a mutation at position 310 was observed, which could potentially affect the protein's function and virus-host interactions. These findings provide valuable insights into the genetic diversity and evolutionary dynamics of CDV in golden jackals, with broader implications for understanding the virus's adaptability to different hosts. Further research is needed to investigate the functional impact of these mutations, particularly their role in vaccine efficacy and disease transmission across wildlife and domestic species.

Molecular Detection of Viral and Bacterial Pathogens in Red Foxes (Vulpes vulpes) from Italy

Animals, including wildlife, are part of One-Health concept since many infectious diseases can affect both humans and animals. In this study, 126 red foxes (Vulpes vulpes) from Northern Italy in 2022-2023 were tested by molecular assays for Protoparvovirus carnivoran 1 (PPVC-1), Canine adenovirus type 1 and 2 (CAdV-1 and CAdV-2), Circovirus canine (CanineCV), Canine distemper virus (CDV), and Leptospira spp. A total of 39 of 126 (30.9%) red foxes were infected with at least one pathogen and five of these were coinfected: 20/126 (15.9%) red foxes tested positive for PPVC-1, 3/126 (2.4%) for CAdV, 20/126 (15.9%) for CanineCV, and 2/126 (1.6%) for Leptospira spp. DNA. No foxes tested positive for CDV RNA. The pathogens identified were genetically analysed. New findings were reported such as a fox with multiple feline panleukopenia virus (FPV) and canine parvovirus type 2b (CPV-2b) infection associated with quasispecies dynamics, typical genetic characteristics of the identified CanineCV, and the first detection in red foxes of Leptospira ST198 related to L. interrogans serogroup Australis. Further studies are necessary to investigate the transmission between domestic animals and wildlife and to understand the role of red foxes in the maintenance of these pathogens not only in the wild but also in urban and peri-urban environments.

Phenotypic Characterization of Encephalitis in the BRAINS of Badgers Naturally Infected with Canine Distemper Virus

Canine distemper virus (CDV) affects a huge diversity of domestic and wild carnivores, with increasing numbers of mortality events worldwide. The local cell-mediated immune response elicited against a natural infection is an important factor in determining the outcome of CDV infection. Therefore, the purposes of this study were to describe the local immune response within the central nervous systems (CNSs) of seven badgers naturally infected with CDV in Asturias (Atlantic Spain) and to determine the phenotype and distribution of microglial cells, T and B lymphocytes, and astrocytes in the foci of gliosis located in the thalamus and cerebellum using immunohistochemistry. The immunohistochemical assessment demonstrated the presence of Iba1-positive microglia and GFAP-positive astrocytes in the foci of gliosis, whereas T (CD3-negative) or B (CD20-negative) lymphocytes in those same lesions were absent. Our results also revealed that the badgers with natural CDV encephalitis presented lesions mostly located in the white matter of the thalamus and cerebellum, suggesting a CDV-specific tropism for the white matter of badger brains in those locations. The knowledge gained in the field of the immunopathogenesis of distemper disease affecting the CNSs of badgers could help to clarify CDV disease patterns in this species.

Canine Distemper Virus Infection in the Free-Living Wild Canines, the Red Fox (Vulpes vulpes) and Jackal (Canis aureus moreoticus), in Croatia

The canine distemper virus (CDV), a paramyxovirus that is closely related to the human measles virus and rinderpest virus of cattle, is a highly contagious viral disease in dogs and wild carnivores worldwide. CDV represents a serious threat to domestic and wild animals, especially to the conservation of endangered wild carnivores. Our study aims to investigate the occurrence of CDV in free-living wild canines in Croatia. For this purpose, 176 red foxes and 24 jackal brain samples collected in the frame of the active surveillance of rabies during winter 2021/2022 were tested. This study provided the first comprehensive overview of the prevalence and spatial distribution of CDV in the wildlife of Croatia, including the molecular phylogenetic analysis of the H gene sequence of field CDV strains circulating in red fox and jackal populations of Croatia. The molecular characterization of hemagglutinin gene genomic regions confirmed the phylogenetic clustering of obtained sequences into the Europa 1 genotype. The obtained CDV red fox sequences were mutually very similar (97.60%). This study indicates the high genetic similarity of Croatian CDV red fox sequences and CDV red fox sequences from Italy and Germany, badger sequences from Germany, polecat sequences from Hungary, and dog sequences from Hungary and Germany.

Biomolecular Analysis of Canine Distemper Virus Strains in Two Domestic Ferrets (Mustela putorius furo)

Canine distemper is a contagious and severe systemic viral disease that affects domestic and wild carnivores worldwide. In this study, two adult female ferrets (Mustela putorius furo) were evaluated for cutaneous lesions. Scab, fur, and swab samples from the external auditory canal, cutaneous lesions, and scrapings were analyzed. Canine distemper virus (CDV)-positive samples underwent RT-PCR/RFLP with the restriction enzyme PsiI, and the hemagglutinin gene sequence was obtained. According to the restriction enzyme and sequence analyses, the viral strains were typed as CDV field strains that are included within the Europe lineage and distinct from those including vaccinal CDV strains. The sequence analysis showed the highest nucleotide identity rates in older Europe lineage CDV strains collected from dogs and a fox in Europe. This study is the first to report on CDV infection in ferrets in southern Italy and contributes to the current knowledge about natural CDV infection in this species. In conclusion, vaccination remains crucial for preventing the disease and counteracting cross-species infection. Molecular biology techniques can enable the monitoring of susceptible wild animals by ensuring the active surveillance of CDV spread.

A One-Year Retrospective Analysis of Viral and Parasitological Agents in Wildlife Animals Admitted to a First Aid Hospital

This study aimed to provide information on the presence and frequency of viral and parasitic agents in wildlife presented to a Veterinary Teaching Hospital in 2020-2021. Serum and faecal samples were collected from 50 rescued animals (roe deer, fallow deer, foxes, badgers, pine martens, and porcupines) and examined by serological, molecular, and parasitological techniques. Transtracheal wash (TTW) was also collected post-mortem from roe deer. Overall, the results of the different techniques showed infections with the following viral and parasitic agents: Bovine Viral Diarrhea Virus, Small Ruminant Lentiviruses, Kobuvirus, Astrovirus, Canine Adenovirus 1, Bopivirus, gastrointestinal strongyles, Capillaria, Ancylostomatidae, Toxocara canis, Trichuris vulpis, Hymenolepis, Strongyloides, Eimeria, Isospora, Dictyocaulus, Angiostrongylus vasorum, Crenosoma, Dirofilaria immitis, Neospora caninum, Giardia duodenalis, and Cryptosporidium. Sequencing (Tpi locus) identified G. duodenalis sub-assemblages AI and BIV in one roe deer and one porcupine, respectively. Adult lungworms collected from the TTW were identified as Dictyocaulus capreolus (COX1 gene). This is the first molecular identification of G. duodenalis sub-assemblage AI and D. capreolus in roe deer in Italy. These results show a wide presence of pathogens in wild populations and provide an overview of environmental health surveillance.

Canine Distemper Virus in Endangered Species: Species Jump, Clinical Variations, and Vaccination

Canine morbillivirus (Canine distemper virus, CDV) is the cause of distemper in a large number of different species, some of which are endangered. The clinical outcome associated with infection is variable and based on many factors, including the host species, the immune response of the individual animal to the infection, and variation in virus tropism and virulence. Unfortunately, the viral characteristics associated with virulence versus attenuation are not fully characterized, nor are the specific mutations that allow this virus to easily move and adapt from one species to another. Due to its wide host range, this virus is difficult to manage in ecosystems that are home to endangered species. Vaccination of the domestic dog, historically considered the reservoir species for this virus, at dog-wildlife interfaces has failed to control virus spread. CDV appears to be maintained by a metareservoir rather than a single species, requiring the need to vaccinate the wildlife species at risk. This is controversial, and there is a lack of a safe, effective vaccine for nondomestic species. This review focuses on topics that are paramount to protecting endangered species from a stochastic event, such as a CDV outbreak, that could lead to extinction.

Detection and sequence analysis of Canine morbillivirus in multiple species of the Mustelidae family

BACKGROUND

Canine morbillivirus (canine distemper virus, CDV) is a member of the Paramyxoviridae family. Canine distemper is a serious viral disease that affects many mammalian species, including members of the Mustelidae family. These animals have an elusive nature, which makes related virological studies extremely challenging. There is a significant knowledge gap about the evolution of their viruses and about the possible effects of these viruses to the population dynamics of the host animals. Spleen and lung tissue samples of 170 road-killed mustelids belonging to six species were collected between 1997 and 2022 throughout Hungary and tested for CDV with real-time RT-PCR.

RESULTS

Three species were positive for viral RNA, 2 out of 64 Steppe polecats (Mustela eversmanii), 1 out of 36 European polecats (Mustela putorius) and 2 out of 36 stone martens (Martes foina); all 18 pine martens (Martes martes), 10 least weasels (Mustela nivalis) and 6 stoats (Mustela erminea) tested negative. The complete CDV genome was sequenced in five samples using pan-genotype CDV-specific, amplicon-based Nanopore sequencing. Based on the phylogenetic analysis, all five viral sequences were grouped to the Europe/South America 1 lineage and the distribution of one sequence among trees indicated recombination of the Hemagglutinin gene. We verified the recombination with SimPlot analysis.

CONCLUSIONS

This paper provides the first CDV genome sequences from Steppe polecats and additional complete genomes from European polecats and stone martens. The infected specimens of various species originated from distinct parts of the country over a long time, indicating a wide circulation of CDV among mustelids throughout Hungary. Considering the high virulence of CDV and the presence of the virus in these animals, we highlight the importance of conservation efforts for wild mustelids. In addition, we emphasize the importance of full genomic data acquisition and analysis to better understand the evolution of the virus. Since CDV is prone to recombination, specific genomic segment analyses may provide less representative evolutionary traits than using complete genome sequences.

Detection and Molecular Characterization of Canine Distemper Virus in Wildlife from Northern Italy

Canine distemper virus (CDV) is a fatal, highly contagious disease found in wild and domestic carnivores. Several outbreaks have occurred in wildlife in Italy in recent years. This study aims to detect CDV in wildlife following the increasing mortality of foxes (Vulpes vulpes) in the Emilia-Romagna region (northern Italy) observed in 2021. Sixty-seven foxes and one badger (Meles meles) were subjected to necropsy followed by histological examination and were analyzed with molecular techniques to detect the presence of CDV. Of the tested animals, 16% (nine foxes and one badger) were positive for CDV. Phylogenetic analysis showed two different lineages based on complete H gene sequences. The Europe/South America-1 lineage was detected in one fox from Modena, which resembled the CDV variant associated with a previous outbreak in northern Italy in 2018, while the European Wildlife lineage was detected in animals from the Rimini province. Amino acid analysis highlighted a Y549H mutation in all sequences collected, which is commonly associated with increased virulence.

Study on the Canine Adenovirus Type 1 (CAdV-1) Infection in Domestic Dogs in Southern Italy

Canine adenovirus type 1 (CAdV-1) is the causative agent of a systemic and potentially fatal viral disease of domestic and wild canids. In Italy, CAdV-1 infection has also been occasionally described in dogs, but information on the epidemiology and its genomic features is still limited. A study was conducted on 291 dogs suspected of infectious gastrointestinal disease. Samples collected from dogs in southern Italy between 2017 and 2020 were analyzed. Virological and histopathological assays were carried out. The presence of CAdVs and other canine viral enteropathogens was investigated, and sequence and phylogenetic analyses were performed. CAdV-1 was detected in six (2.1%) dead stray dogs alone or in mixed infections with other viruses. Gross lesions and histopathological findings referred to CAdV infection were observed, also involving the central nervous system tissues. All inoculated samples were successfully isolated. Sequence analysis evidenced divergences with the circulating strains previously described in Italy and a closer relation with older CAdV-1 strains collected from other countries, suggesting a genetic heterogeneity of CAdV-1 in Italy. The evidence of the circulation of CAdV-1 and its genomic features allows us to have more in-depth knowledge of the epidemiology and evolution of the CAdV-1 genomic variants.

Canine Distemper Virus in Autochtonous and Imported Dogs, Southern Italy (2014–2021)

Simple Summary

In the period 2014–2021, the circulation of CDV in dogs of Southern Italy was investigated. In this time span a reduction in the circulation of CDV was observed, with a higher frequency of detection of the pathogen in imported dogs (18.4%) compared to stray (7.4%) and household (3.9%) animals. These results underline the effectiveness of the prophylaxis strategy on autochthonous dogs as well as the importance of continuous surveillance of CDV, especially in imported dogs.

Abstract

This study aims to investigate the presence of canine distemper virus (CDV) infection in 949 autochthonous or illegally imported dogs from Southern Italy, over a period of eight years (2014–2021). CDV RNA was detected in 6.8% (65/949) of the animals tested, with no detection of CDV in dogs sampled in 2020–2021. The frequency of CDV detection was higher in imported dogs (19/103, 18.3%) with respect to stray (27/365, 7.4%) and household dogs (19/481, 3.9%). On sequence and phylogenetic analyses of selected strains, the analyzed viruses belonged to the Arctic clade, which has already been reported in Italy and in Europe. The results of our study may suggest a reduction of CDV circulation in Southern Italy, while at the same time highlighting the need for strict controls on dog importation, in order to prevent the introduction of viruses from endemic countries.

Molecular Detection and Phylogenetic Analysis of Canine Distemper Virus in Marsican Brown Bear (Ursus arctos marsicanus)

Simple Summary

Marsican brown bear is a subspecies of Eurasian bear, that lives in a few areas of Central Italy, with an estimated population of only 50 animals. For this reason, it is considered one of the most threatened Italian mammals, and specific Conservation Plans are applied with the focus to fight the mortality causes, mainly related to human activities or illegal practices. On the contrary, few reports describing infectious or parasitic diseases in Marsican brown bears are available. Among pathogens, the canine distemper virus (CDV) is responsible for a contagious and multi-organ disease, able to infect a wide range of domestic and wild carnivores. In 2013 a fatal outbreak of distemper was registered in Central Italy, involving dogs, Apennine wolves, badgers, and foxes, but apparently without any consequences for the Marsican brown bears living in the same territories. In this paper, we describe the first CDV infection detected in a live-trapped bear. The identified strain resulted in similarities to CDV recovered from foxes and dogs of the same area. Even if no clinical signs referred to the disease have been detected in the monitored bear, the evidence of a viral pathogen potentially able to menace the conservation of the Marsican brown bear population highlights the importance of continuing observation activities.

Abstract

In this paper, we report the first molecular detection of the canine distemper virus in the Marsican brown bear (Ursus arctos marsicanus). Three subadults and one adult were live-trapped and checked for the main viral pathogens responsible for infectious diseases in this species. The four bears were found to be negative for all investigated viruses except for one, which resulted in a positive outcome for CDV by means of RT-PCR targeting fragments of viral N and H genes. The sequence analysis revealed the specificity of amplicons for the Europe Wildlife lineage of CDV, the same viral strain recovered from three foxes and two unvaccinated dogs coming from the same territories where the positive bear was captured. These results confirm the receptivity of Marsican brown bear for CDV, apparently without any pathological consequences for the positive animal, and suggest the presence in the studied area of a unique wild host-adapted lineage of the virus, able to spread in domestic animals, too. In this respect, continuous and specifically targeted surveillance systems are necessary in order to highlight any changes in the epidemiology of the infection in the territories where the Marsican brown bear lives, along with a more effective vaccination program for domestic dogs co-existing with this endangered species.

Retrospective Detection and Complete Genomic Sequencing of Canine morbillivirus in Eurasian Otter (Lutra lutra) Using Nanopore Technology

The Eurasian otter (Lutra lutra) is a piscivorous apex predator in aquatic habitats, and a flagship species of conservation biology throughout Europe. Despite the wide distribution and ecological relevance of the species, there is a considerable lack of knowledge regarding its virological and veterinary health context, especially in Central Europe. Canine morbillivirus (Canine distemper virus (CDV)) is a highly contagious viral agent of the family Paramyxoviridae with high epizootic potential and veterinary health impact. CDV is present worldwide among a wide range of animals; wild carnivores are at particular risk. As part of a retrospective study, lung-tissue samples (n = 339) from Eurasian otters were collected between 2000 and 2021 throughout Hungary. The samples were screened for CDV using a real-time RT-PCR method. Two specimens proved positive for CDV RNA. In one sample, the complete viral genome was sequenced using a novel, pan-genotype CDV-specific amplicon-based sequencing method with Oxford Nanopore sequencing technology. Both viral sequences were grouped to a European lineage based on the hemagglutinin-gene phylogenetic classification. In this article, we present the feasibility of road-killed animal samples for understanding the long-term dynamics of CDV among wildlife and provide novel virological sequence data to better understand CDV circulation and evolution.

Pathogen Screening for Possible Causes of Meningitis/Encephalitis in Wild Carnivores From Saxony-Anhalt

Inflammation in meninges and/or brain is regularly noticed in red foxes and other wild carnivores during rabies control programs. Despite negative rabies virus (RABV) results, the etiologies of these cases remain unknown. Thus, the aim of this study was to provide an overview of the occurrence of pathogens that may cause diseases in the brains of wild carnivores and pose a risk to humans and other animals. In addition to RABV and canine distemper virus (CDV), a variety of pathogens, including members of Flaviviridae, Bornaviridae, Herpesviridae, Circoviridae, as well as bacteria and parasites can also cause brain lesions. In 2016 and 2017, brain samples of 1,124 wild carnivores were examined by direct fluorescent antibody test for RABV as well as (reverse-transcriptase) quantitative polymerase chain reaction (PCR) for the presence of CDV as part of a monitoring program in Saxony-Anhalt, Germany. Here, we applied similar methods to specifically detect suid herpesvirus 1 (SuHV-1), West Nile virus (WNV), Borna disease virus 1 (BoDV-1), canid alphaherpesvirus 1 (CaHV-1), canine parvovirus type 2 (CPV-2), fox circovirus (FoxCV), and Neospora caninum (N. caninum). Further, bacteriogical examination for the existence of Listeria monocytogenes (L. monocytogenes) and immunohistochemistry of selected cases to detect Toxoplasma gondii (T. gondii) antigen were performed. Of all pathogens studied, CDV was found most frequently (31.05%), followed by FoxCV (6.80%), CPV-2 (6.41%), T. gondii (4/15; 26.67%), nematode larvae (1.51%), L. monocytogenes (0.3%), and various other bacterial pathogens (1.42%). In 68 of these cases (6.05%), multiple pathogen combinations were present simultaneously. However, RABV, WNV, BoDV-1, SuHV-1, CaHV-1, and N. caninum were not detected. The majority of the histopathological changes in 440 animals were inflammation (320/440; 72.73%), predominantly non-suppurative in character (280/320; 87.50%), and in many cases in combination with gliosis, satellitosis, neuronophagia, neuronal necrosis, and/or vacuolization/demyelination, or in single cases with malacia. Thus, it could be shown that wild carnivores in Saxony-Anhalt are carriers mainly for CDV and sometimes also for other, partly zoonotic pathogens. Therefore, the existing monitoring program should be expanded to assess the spill-over risk from wild carnivores to humans and other animals and to demonstrate the role of wild carnivores in the epidemiology of these zoonotic pathogens.

Stress-Related Herpesvirus Reactivation in Badgers Can Result in Clostridium Proliferation

Clostridium perfringens is an important food-borne zoonotic pathogen and a member of the commensal gut microbiome of many mammals. Predisposing factors such as coinfection with other pathogens or diet change can, however, cause overgrowth and subsequent disease development. Here we investigated the occurrence of C. perfringens in a free-ranging badger population with up to 100% prevalence of herpesvirus infection. Herpesvirus reactivation is known to be associated with increased susceptibility bacterial infections. PCR screening of rectal swabs from 69 free-ranging badgers revealed 15.9% (11/69, 95% CI = 9.1-26.3%) prevalence of detectable C. perfringens (Type A) DNA in the digestive tracts of assymptomatic animals. The results of Fisher's exact test revealed C. perfringens detection was not biased by age, sex and seasons. However, badgers with genital tract gammaherpesvirus (MusGHV-1) reactivation (p = 0.007) and infection with a specific MusGHV-1 genotype (p = 0.019) were more prone to of C. perfringens proliferation, indicating coinfection biased dynamics of intestinal C. perfringens. An inclusion pattern analysis further indicated that, causally, MusGHV-1 reactivation potentiated C. perfringens detection. Whether or not specific MusGHV-1 genotype infection or reactivation plays a role in C. perfringens overgrowth or disease development in badgers will require further investigation. Nevertheless, a postmortem examination of a single badger that died of fatal disease, likely associated with C. perfringens, revealed MusGHV-1 detection in the small intestine.

Canine distemper virus in wildlife in south-western Europe

Multi-host pathogens emerging and re-emerging at the wildlife-domestic animal interface affect wildlife management and conservation. This is the case of canine distemper virus (CDV), a paramyxovirus closely related to human measles virus and rinderpest virus of cattle. With an area of 10,603 km² , Asturias region in Atlantic Spain is a hotspot of carnivore diversity, which includes the largest Eurasian brown bear (Ursus arctos arctos) population and one of the largest wolf (Canis lupus) populations in south-western Europe. In 2020-2021, we recorded mortality due to distemper in four carnivore species including three mustelids (Eurasian badger Meles meles, European marten Martes martes and European polecat Mustela putorius) and one canid (red fox, Vulpes vulpes). Clinical signs and pathology were similar across species and consistent with the emergence of a highly pathogenic viral strain, with CDV antigen mainly located in the central nervous system, lungs, spleen and lymph nodes. A molecular study in eight wild carnivore species, also including the Iberian wolf, Eurasian brown bear, American mink (Neovison vison) and stone marten (Martes foina), revealed 19.51% (16/82) of positivity. Phylogenetic analysis demonstrated that CDV belonged to the previously described European lineage. A retrospective serosurvey (2008-2020) showed a high seroprevalence of CDV antibodies (43.4%) in 684 analyzed badgers, indicating a long-term though not stable viral circulation in this multi-host community. The possible triggers of the 2020-2021 outbreak and the implications for carnivore management and conservation are discussed.

New members to Arctic-like lineage of canine distemper virus from Turkey

Canine distemper virus (CDV) causes a multisystemic fatal disease, briefly named as distemper, in domestic and wild animals. Molecular characterization studies serve to identify local strains, accordingly, helps to determine the scope of vaccination in prevention of distemper. We aimed with this study to update the molecular status of CDV in domestic dogs in Turkey. Sequence analysis of the H gene revealed that novel Turkish sequences formed a separated clade in Arctic-like lineage. Italian clade which mainly included strains originated from wild canid or non-canid localized nearly to novel Turkish clade. Codons 530th and 549th determining the affinity of domestic or wild animals to distemper were Asparagine and Tyrosine, respectively. This report presented the presence of CDV strains belonging to Arctic-like lineage for the first time in domestic dogs in Turkey. The findings pave the way for the reassessment of the circulation and geographical shifting of Arctic-like lineages of CDV.

Prolonged Infection of Canine Distemper Virus in a Mixed-Breed Dog

Canine distemper virus (CDV) is a major viral pathogen in domestic dogs, belonging to the Paramyxoviridae family, in the Morbillivirus genus. It is present worldwide, and a wide range of domestic animals and wild carnivores are at risk. In the absence of vaccination, dogs have a low chance of survival; however, if and when a dog survives, it can take an average of a few weeks to a few months to fully wipe out the virus. In the present study, we traced the course of infection of a 1-year-old mixed-breed male dog. The animal had an unusually long course of persistent CDV infection with a vector-borne heartworm (Dirofilaria immitis) co-infection. The dog excreted the CDV for 17 months with PCR positivity in urine samples collected from February 2019 through June 2020. The sequencing and phylogenetic analysis of the hemagglutinin gene revealed the CDV to be the member of the endemic Arctic-like genetic lineage. To the best of our knowledge, this report represents the longest documented canine infection of CDV. Notably, we highlight the necessity regarding CDV infectivity studies to better comprehend the transmission attributes of the virus.

A Canine Distemper Virus Retrospective Study Conducted from 2011 to 2019 in Central Italy (Latium and Tuscany Regions)

Canine distemper virus (CDV) is a highly lethal contagious viral pathogen mainly found in domestic and wild canids and mustelids. Although, in Italy, circulating strains of Europe 1, Europe wildlife and Arctic type are reported, data relating to Latium and Tuscany regions are limited. In view of this, through passive surveillance, we investigated the presence of CDV and which strains were circulating in these Regions. From March 2017 to October 2019, a group of 122 subjects were tested for CDV using a PCR protocol described in the literature, with 12 detected positive; analyses were carried out on a set of target samples (brain and lung, conjunctival, nasal and rectal swabs, urine or swab from bladder and intracardiac clot) that was defined for the detection of CDV in both live and dead animals. The rectal swab, easily collected also from live animals, represented the most suitable sample for CDV diagnosis, with 9 positive of the 11 (81.82%) tested. In addition, brain and lung of 15 subjects out of 181 susceptible animals collected between 2011 and 2018, during post mortem investigations in routine diagnostic activity, were CDV positive. Molecular analyses of all positive samples, using a 287 bp fragment located within the conserved N terminus of the morbillivirus nucleoprotein gene, detected the circulation of strain CDV599/2016 (KX545421.1) belonging to the “Europe wildlife” lineage, and of strain CDV12254/2015 (KX024709.1), belonging to the Arctic-lineage, thus confirming the co-circulation of the two lineages, as already noted in previous studies.

Infectious Diseases and Wildlife Conservation Medicine: The Case of the Canine Distemper in European Wolf Population

Canine distemper is a contagious infectious disease, caused by canine distemper virus (CDV) belonging to Morbillivirus genus, Paramyxoviridae family, representing a serious threat for domestic and wild carnivores [...]

Canine parvovirus vaccination and immunisation failures: Are we far from disease eradication?

Despite extensive vaccination, canine parvovirus (CPV) remains a leading infectious cause of canine mortality, especially among juveniles. This review provides an update on CPV vaccine types and vaccination protocols. The design of CPV prevention strategies and vaccination programs with a goal of herd immunity has been hampered by deficiencies of studies that model companion animal viral infections and inform an understanding of the basic reproduction number. However, the most important issue in eradication of CPV disease is represented by immunisation failures including: i) the presence of interfering titres of maternally-derived antibodies; ii) the presence of non-responders; and iii) possible reversion to virulence. In contrast, the role of the CPV variants in immunisation failures is widely debated. Taking into account the reduced circulation of canine distemper virus and canine adenovirus type 1 in countries where extensive vaccination is carried out, more effort should be made to aim for CPV eradication, including antibody testing to determine the optimal time for vaccinations of pups and adults and homogeneous vaccine coverage of dog population.

The Canine Morbillivirus Strain Associated with An Epizootic in Caspian Seals Provides New Insights into the Evolutionary History of this Virus

Canine morbillivirus (canine distemper virus; CDV) is a worldwide distributed morbillivirus that causes sporadic cases and recurrent epizootics among an increasing number of wild, feral, and domestic animal species. We investigated the evolutionary history of CDV strains involved in the 1988 Lake Baikal (CDVPS88) and the 2000 Caspian Sea (CDVPC00) seal die-offs by recovery of full-length sequences from archived material using next-generation sequencing. Bayesian phylogenetic analyses indicated that CDVPC00 constitutes a novel strain in a separate clade (tentatively termed "Caspian") from the America-1 clade, which is comprised of older vaccine strains. The America-1/Caspian monophyletic group is positioned most basally with respect to other clades and is estimated to have separated from other CDV clades around 1832. Our results indicate that CDVPC00 recovered from the epizootic in the Caspian Sea in 2000 belongs to a previously undetected novel clade and constitutes the most ancestral wild-type CDV clade.

Diagnosis and characterization of canine distemper virus through sequencing by MinION nanopore technology

Prompt identification of the causative pathogen of an infectious disease is essential for the choice of treatment or preventive measures. In this perspective, nucleic acids purified from the brain tissue of a dog succumbed after severe neurological signs were processed with the MinION (Oxford Nanopore Technologies, Oxford UK) sequencing technology. Canine distemper virus (CDV) sequence reads were detected. Subsequently, a specific molecular test and immunohistochemistry were used to confirm the presence of CDV RNA and antigen, respectively, in tissues. This study supports the use of the NGS in veterinary clinical practice with potential advantages in terms of rapidity and broad-range of molecular diagnosis.

Antigenic analysis of genetic variants of Canine distemper virus

Canine distemper virus (CDV) is an RNA virus of the genus Morbillivirus within the family Paramyxoviridae. CDV produces multi-systemic disease in dogs and other terrestrial carnivores. With the development of modified live vaccines in the 1950s and 1960s, the disease, with a few exceptions, has been successfully controlled. However, recently the cases of CDV in vaccinated dogs have been increasing throughout the world, including the United States. There are many reasons that can lead to vaccine failure, including antigenic differences between the vaccine strains and the currently circulating wild-type strains. Currently, there are at least three genetically different CDV lineages circulating in the US. Therefore, in this study, we evaluated various wild-type CDV and vaccine isolates to determine if the genetic differences observed among various strains result in significant antigenic differences based on changes to the neutralizing epitopes. The results of a cross-neutralization assay revealed that there are antigenic differences among the tested CDV wild-type isolates as well as between the tested isolates and the vaccine strains currently used in the US. Therefore, these results suggest the need to develop an updated CDV vaccine.