The relationship between reported domestic canine parvovirus cases and wild canid distribution

Global distribution, cross-species transmission, and receptor binding of canine parvovirus-2: Risks and implications for humans

For canine parvovirus -2 (CPV-2), a zoonotic virus capable of cross-species transmission in animals, the amino acid changes of capsid protein VP2 are key factors when binding to other species' transferrin receptors (TfR). CPV-2 variants can spread from felines and canines, for example, to Carnivora, Artiodactyla, and Pholidota species, and CPV-2c variants are essential to spread from Carnivora to Artiodactyla and Pholidota species in particular. In our study, a CPV-2a variant maintained a relatively stable trend, and the proportion of CPV-2c gradually rose from 1980 to 2021. The VP2 amino acid sequence analysis showed that five amino acid mutations at 426E/D, 305H/D, and 297S may be necessary for the virus to bind to different host receptors. Meanwhile, receptor-binding loop regions and amino acid sites 87 L, 93 N, 232I, and 305Y were associated with CPV-2 cross-species transmission. The homology of TfRs in different hosts infected with CPV-2 ranged from 77.2 % to 99.0 %, and from pig to feline, canine, and humans was 80.7 %, 80.4 %, and 77.2 %, respectively. The amino acid residues of TfRs involved in the viral binding in those hosts are highly conserved, which suggests that CPV-2 may be capable of pig-to-human transmission. Our analysis of the origin, evolutionary trend, cross-species transmission dynamics, and genetic characteristics of CPV-2 when binding to host receptors provides a theoretical basis for further research on CPV-2's mechanism of cross-species transmission and for establishing an early warning and monitoring mechanism for the possible threat of CPV-2 to animal-human public security.

Embedding research and enquiry in Australian DVM curriculum

Research and enquiry (R&E) is an integral part of veterinary training. It is a foundation of evidence-based practice. In the University of Sydney Doctor of Veterinary Medicine degree R&E culminates in a cap-stone experience in Year 3: a 'professionally focused project', a student-driven and academic supported individual research project. The project provides an authentic experience within a veterinary discipline. Students work with an academic advisor who provides guidance for developing and achieving meaningful educational and professional goals. Successful advising depends upon a shared understanding of, and commitment to, the advising process by students, advisors and the university. The R&E mission can be broadly defined as - veterinarians recognise that evidence-based approach to practice, which is based on the scientific method, leads to the generation of new knowledge that underpins the veterinary medical profession.

First isolation and molecular characterization of canine parvovirus-type 2b (CPV-2b) from red foxes (Vulpes vulpes) living in the wild habitat of Turkey

BACKGROUND

The canine parvovirus, with its many variants, is responsible for a pivotal and common viral infection affecting millions of dogs and other carnivore species worldwide, particularly the wild ones, which are considered as the main reservoir hosts. To that end, this study investigated the presence of canine parvovirus (CPV) in red foxes (Vulpes vulpes) living in wild habitats of several regions of Turkey.

METHODS

We randomly collected 630 archival fox stool specimens from rural areas of 22 provinces and used real-time PCR to detect CPV.

RESULTS

Two of the 630 (0.3%) stool samples were positive for CPV-DNA, named Tr-Fox/128(Aydın) and Tr-Fox/159(Manisa). We attempted to isolate the virus in a MDCK cell line, and cytopathic effects were observed four days post-inoculation. Three regions corresponding to the CPV capsid protein VP2 gene from extracted DNA of positive samples were amplified by conventional PCR, and the products were visualised, purified, and Sanger sequenced. Three overlapping DNA raw sequence fragments, were read, assembled, and aligned to obtain approximately 1.5 kb-long regions that cover most of the VP2 gene, then deposited in GenBank. After comparing the isolates with parvovirus sequences data of domestic and wild carnivores by BLAST processing, our isolates' similarity rate with each other was 99.40%, with base differences in 9 nucleotide positions. They were classified as 2b variant closely related to isolates from dogs in Turkey, Egypt, Iraq, Italy, Thailand, and China.

CONCLUSION

This study presents evidence of interspecies transmission of CPV, of which there are no reports on prevalence in wildlife carnivores of our country. Identification of CPV in red foxes threatens local and hunting dogs, which may contract the infection or disseminate it to other wild animal species or vice-versa.

Circulation of diverse protoparvoviruses in wild carnivores, Italy

Protoparvovirus is a monophyletic viral genus that includes the species Carnivore protoparvovirus-1 infecting domestic and wild carnivores. In this paper, the results of an epidemiological survey for Carnivore protoparvovirus-1 in wild carnivores in Italy are reported. Overall, 34 (11.4%) out of 297 tested animals were positive for Carnivore protoparvovirus-1, but the frequency of detection was much higher in intestine (54%) than in spleen samples (2.8%), thus suggesting that the intestine is the best sample to collect from wild animals for parvovirus detection. Feline panleukopenia virus (FPV) was detected in red foxes (Vulpes vulpes) (2.8%, 7/252) and Eurasian badgers (Meles meles) (10%, 1/10), whilst canine parvovirus (CPV) was found in wolves (54.3%, 19/35), Eurasian badgers (60%, 6/10) and one beech marten (Martes foina) (100%, 1/1), with more than one parvovirus type detected in some animals. Protoparvoviral DNA sequences from this study were found to be related to CPV/FPV strains detected in Asia and Europe, displaying some amino acid changes in the main capsid protein VP2 in comparison with other parvovirus strains from wildlife. In particular, the two most common mutations were Ile418Thr and Ala371Gly, which were observed in 6/12 (50%) and 5/12 (41.7%) of the CPV sequences from this study. Continuous surveillance for parvoviruses in wild carnivores and genetic analysis of the detected strains may help obtain new insight into the role of these animals in the evolution and epidemiology of carnivore parvoviruses.

Virome of crab-eating (Cerdocyon thous) and pampas foxes (Lycalopex gymnocercus) from southern Brazil and Uruguay

Crab-eating (Cerdocyon thous) and Pampas foxes (Lycalopex gymnocercus) are wild canids distributed in South America. Domestic dogs (Canis lupus familiaris) and wild canids may share viral pathogens, including rabies virus (RABV), canine distemper virus (CDV), and canine parvovirus 2 (CPV-2). To characterize the virome of these wild canid species, the present work evaluated the spleen and mesenteric lymph node virome of 17 crab-eating and five Pampas foxes using high-throughput sequencing (HTS). Organ samples were pooled and sequenced using an Illumina MiSeq platform. Additional PCR analyses were performed to identify the frequencies and host origin for each virus detected by HTS. Sequences more closely related to the Paramyxoviridae, Parvoviridae and Anelloviridae families were detected, as well as circular Rep-encoding single-stranded (CRESS) DNA viruses. CDV was found only in crab-eating foxes, whereas CPV-2 was found in both canid species; both viruses were closely related to sequences reported in domestic dogs from southern Brazil. Moreover, the present work reported the detection of canine bocavirus (CBoV) strains that were genetically divergent from CBoV-1 and 2 lineages. Finally, we also characterized CRESS DNA viruses and anelloviruses with marked diversity. The results of this study contribute to the body of knowledge regarding wild canid viruses that can potentially be shared with domestic canids or other species.

A history of canine parvovirus in Australia: what can we learn?

Canine parvovirus (CPV) has been reported throughout the world since the late 1970s. Published information was reviewed to draw insights into the epidemiology, pathogenesis, diagnosis, treatment and outcomes of CPV disease in Australia and the role of scientific research on CPV occurrence, with key research discoveries and knowledge gaps identified. Australian researchers contributed substantially to early findings, including the first reported cases of parvoviral myocarditis, investigations into disease aetiopathogenesis, host and environmental risk factors and links between CPV and feline panleukopenia. Two of the world's first CPV serological surveys were conducted in Australia and a 1980 national veterinary survey of Australian and New Zealand dogs revealed 6824 suspected CPV cases and 1058 deaths. In 2010, an Australian national disease surveillance system was launched; 4940 CPV cases were reported between 2009 and 2014, although underreporting was likely. A 2017 study estimated national incidence to be 4.12 cases per 1000 dogs, and an annual case load of 20,110 based on 4219 CPV case reports in a survey of all Australian veterinary clinics, with a 23.5% response rate. CPV disease risk factors identified included socioeconomic disadvantage, geographical location (rural/remote), season (summer) and rainfall (recent rain and longer dry periods both increasing risk). Age <16 weeks was identified as a risk factor for vaccination failure. Important knowledge gaps exist regarding national canine and feline demographic and CPV case data, vaccination coverage and population immunity, CPV transmission between owned dogs and other carnivore populations in Australia and the most effective methods to control epizootics.

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.

Phylogenetic and Geospatial Evidence of Canine Parvovirus Transmission between Wild Dogs and Domestic Dogs at the Urban Fringe in Australia

Canine parvovirus (CPV) is an important cause of disease in domestic dogs. Sporadic cases and outbreaks occur across Australia and worldwide and are associated with high morbidity and mortality. Whether transmission of CPV occurs between owned dogs and populations of wild dogs, including Canis familiaris, Canis lupus dingo and hybrids, is not known. To investigate the role of wild dogs in CPV epidemiology in Australia, PCR was used to detect CPV DNA in tissue from wild dogs culled in the peri-urban regions of two Australian states, between August 2012 and May 2015. CPV DNA was detected in 4.7% (8/170). There was a strong geospatial association between wild-dog CPV infections and domestic-dog CPV cases reported to a national disease surveillance system between 2009 and 2015. Postcodes in which wild dogs tested positive for CPV were 8.63 times more likely to also have domestic-dog cases reported than postcodes in which wild dogs tested negative (p = 0.0332). Phylogenetic analysis of CPV VP2 sequences from wild dogs showed they were all CPV-2a variants characterized by a novel amino acid mutation (21-Ala) recently identified in CPV isolates from owned dogs in Australia with parvoviral enteritis. Wild-dog CPV VP2 sequences were compared to those from owned domestic dogs in Australia. For one domestic-dog case located approximately 10 km from a wild-dog capture location, and reported 3.5 years after the nearest wild dog was sampled, the virus was demonstrated to have a closely related common ancestor. This study provides phylogenetic and geospatial evidence of CPV transmission between wild and domestic dogs in Australia.