Canine distemper virus (CDV) is a worldwide distributed virus which belongs to the genus Morbillivirus within the Paramyxoviridae family. CDV spreads through the lymphatic, epithelial, and nervous systems of domestic dogs and wildlife, in at least six orders and over 20 families of mammals. Due to the high morbidity and mortality rates and broad host range, understanding the epidemiology of CDV is not only important for its control in domestic animals, but also for the development of reliable wildlife conservation strategies. The present review aims to give an outlook of the multiple evolutionary landscapes and factors involved in the transmission of CDV by including epidemiological data from multiple species in urban, wild and peri-urban settings, not only in domestic animal populations but at the wildlife interface. It is clear that different epidemiological scenarios can lead to the presence of CDV in wildlife even in the absence of infection in domestic populations, highlighting the role of CDV in different domestic or wild species without clinical signs of disease mainly acting as reservoirs (peridomestic and mesocarnivores) that are often found in peridomestic habits triggering CDV epidemics. Another scenario is driven by mutations, which generate genetic variation on which random drift and natural selection can act, shaping the genetic structure of CDV populations leading to some fitness compensations between hosts and driving the evolution of specialist and generalist traits in CDV populations. In this scenario, the highly variable protein hemagglutinin (H) determines the cellular and host tropism by binding to signaling lymphocytic activation molecule (SLAM) and nectin-4 receptors of the host; however, the multiple evolutionary events that may have facilitated CDV adaptation to different hosts must be evaluated by complete genome sequencing. This review is focused on the study of CDV interspecies transmission by examining molecular and epidemiological reports based on sequences of the hemagglutinin gene and the growing body of studies of the complete genome; emphasizing the importance of long-term multidisciplinary research that tracks CDV in the presence or absence of clinical signs in wild species, and helping to implement strategies to mitigate the infection. Integrated research incorporating the experience of wildlife managers, behavioral and conservation biologists, veterinarians, virologists, and immunologists (among other scientific areas) and the inclusion of several wild and domestic species is essential for understanding the intricate epidemiological dynamics of CDV in its multiple host infections.

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Evolution and Interspecies Transmission of Canine Distemper Virus-An Outlook of the Diverse Evolutionary Landscapes of a Multi-Host Virus.

https://biblio.ugent.be/publication/8550758/file/8550759.pdf

A new look at an old dog : Bonn-Oberkassel reconsidered

Canine distemper (CD) is one of the highly contagious and invariably fatal viral diseases of dogs and other carnivores. Despite the widespread use of modified live vaccines to control CD, the prevalence of disease has increased at an alarming rate in recent years. Although a number of factors may be ascribed for vaccine failure, antigenic differences among the vaccine and wild-type strains have gained the interest of researchers. Considering the high genetic variability of haemagglutinin gene (H gene) and its role in eliciting the immune response to canine distemper virus (CDV), we have generated nine full-length CDV H gene sequences from infected dogs including three vaccinated cases. Bayesian analysis was performed using 102 full-length H gene nucleotide sequences over a time frame of 76 years (1940-2016) from 18 countries. The time to the most recent common ancestor (tMRCA) of CDV was estimated to be 1696 AD. Phylogenetic reconstruction clustered Indian wild-type viruses into a distinct monophyletic group clearly separated from the previously established CDV lineages. This signifies the presence of a novel genetic variant (proposed as "Lineage India-1/Asia-5") circulating among dog population in India. To investigate the importance of substitutions at amino acid residues 530 and 549 of CDV H protein in determining the host switches from canid to non-canid hosts, we analysed 125 H gene sequences including nine sequences generated in this study. Selection pressure analysis and analysis of amino acid sequences revealed a trend towards adaptation of 549H variants in non-canid hosts although no role of G/E530R/D/N substitution could be identified. This is the first comprehensive study about the nature and ecology of CDV circulating among dog population in India. Outbreaks in vaccinated animals as observed in this study have raised a concern towards the effectiveness of current vaccine strains warranting detailed investigation.

Phylogenetic analysis of haemagglutinin gene deciphering a new genetically distinct lineage of canine distemper virus circulating among domestic dogs in India

Canine distemper virus (CDV) is the cause of a multisystem disease in domestic dogs and wild animals, infecting more than 20 carnivore and non-carnivore families and even infecting human cell lines in in vitro conditions. Phylogenetic classification based on the hemagglutinin gene shows 17 lineages with a phylogeographic distribution pattern. In Medellin (Colombia), the lineage South America-3 is considered endemic. Phylogenetic studies conducted in Ecuador using fragment coding for the fusion protein signal peptide (Fsp) characterized a new strain belonging to a different lineage. For understanding the distribution of the South America-3 lineage in the north of the South American continent, we characterized CDV from three Colombian cities (Medellin, Bucaramanga, and Bogota). Using phylogenetic analysis of the hemagglutinin gene and the Fsp region, we confirmed the circulation of CDV South America-3 in different areas of Colombia. We also described, for the first time to our knowledge, the circulation of a new lineage in Medellin that presents a group monophyletic with strains previously characterized in dogs in Ecuador and in wildlife and domestic dogs in the United States, for which we propose the name “South America/North America-4” due its intercontinental distribution. In conclusion, our results indicated that there are at least four different CDV lineages circulating in domestic dogs in South America: the Europe/South America-1 lineage circulating in Brazil, Uruguay, and Argentina; the South America-2 lineage restricted to Argentina; the South America-3 lineage, which has only been reported in Colombia; and lastly an intercontinental lineage present in Colombia, Ecuador, and the United States, referred to here as the “South America/North America-4” lineage.

/pdf/phylogenetic-evidence-of-the-intercontinental-circulation-of-2ol2b391pw.pdf

Phylogenetic evidence of the intercontinental circulation of a Canine distemper virus lineage in the Americas

The Bonn-Oberkassel dog remains (Upper Pleistocene and 14223 þ- 58 years old) have been reportedmore than 100 years ago. Recent re-examination revealed the tooth of another older and smaller dog,making this domestic dog burial not only the oldest known, but also the only one with remains of twodogs. This observation brings the total known Magdalenian dogs to nine.Domestication of dogs during the final Palaeolithic has important implications for understanding pre-Holocene hunter-gatherers. Most proposed hunter-gatherer motivations for domesticating dogs havebeen utilitarian. However, remains of the Bonn-Oberkassel dogs may offer another view.The Bonn-Oberkassel dog was a late juvenile when it was buried at approximately age 27e28 weeks,with two adult humans and grave goods. Oral cavity lesions indicate a gravely ill dog that likely suffered amorbillivirus (canine distemper) infection. A dental line of suggestive enamel hypoplasia appears at the19-week developmental stage. Two additional enamel hypoplasia lines, on the canine only, documentfurther disease episodes at weeks 21 and 23. Pathological changes also include severe periodontal diseasethat may have been facilitated by immunodeficiency.Since canine distemper has a three-week disease course with very high mortality, the dog must havebeen perniciously ill during the three disease bouts and between ages 19 and 23 weeks. Survival withoutintensive human assistance would have been unlikely. Before and during this period, the dog cannot haveheld any utilitarian use to humans.We suggest that at least some Late Pleistocene humans regarded dogs not just materialistically, butmay have developed emotional and caring bonds for their dogs, as reflected by the survival of this dog,quite possibly through human care.

A new look at an old dog: Bonn-Oberkassel reconsidered

Canine distemper virus (CDV) has emerged as a significant disease of wildlife, which is highly contagious and readily transmitted between susceptible hosts. Initially described as an infectious disease of domestic dogs, it is now recognized as a global multi-host pathogen, infecting and causing mass mortalities in a wide range of carnivore species. The last decade has seen the effect of numerous CDV outbreaks in various wildlife populations. Prevention of CDV requires a clear understanding of the potential hosts in danger of infection as well as the dynamic pathways CDV uses to gain entry to its host cells and its ability to initiate viral shedding and disease transmission. We review recent research conducted on CDV infections in wildlife, including the latest findings on the causes of host specificity and cellular receptors involved in distemper pathogenesis.

Angelika K. Loots

Papers

Advances in canine distemper virus pathogenesis research: a wildlife perspective.

The role of toll-like receptor polymorphisms in susceptibility to canine distemper virus