Molecular characterization of canine parvovirus and canine enteric coronavirus in diarrheic dogs on the island of St. Kitts: First report from the Caribbean region

Epidemiological investigation of enteric canine coronaviruses in domestic dogs: A systematic review and meta-analysis

Canine enteric coronavirus (CeCoV) is a globally distributed enteric pathogen that causes significant harm to canines. The objective of this systematic review was to examine the global dissemination of CeCoV and assess the potential for infected canines to be exposed to various CeCoV genotypes and subtypes. With an aggregated prevalence of 18.8%, the study predicted regional variations, indicating that CeCoV is an exceptionally prevalent disease. The increased likelihood that infected canines will be asymptomatic is a significant cause for concern, as undetected cases of CeCoV infection could persist and spread the disease. This underscores the significance of ongoing surveillance of CeCoV in order to avert its transmission. Nevertheless, further investigation is necessary in order to ascertain the moderators that significantly impact the prevalence and distribution of distinct subtypes and genotypes of CeCoV. Hence, it is imperative to undertake randomized clinical trials in order to acquire a more accurate understanding of the variables that influence the prevalence of CeCoV. By conducting ongoing surveillance, regional variations in the prevalence of CeCoV in canines can be accounted for, thereby enhancing our comprehension of the illness and ultimately impeding its transmission.

A comprehensive review of viruses in terrestrial animals from the Caribbean islands of Greater and Lesser Antilles

Viruses pose a major threat to animal health worldwide, causing significant mortalities and morbidities in livestock, companion animals and wildlife, with adverse implications on human health, livelihoods, food safety and security, regional/national economies, and biodiversity. The Greater and Lesser Antilles consist of a cluster of islands between the North and South Americas and is habitat to a wide variety of animal species. This review is the first to put together decades of information on different viruses circulating in companion animals, livestock, and wildlife from the Caribbean islands of Greater and Lesser Antilles. Although animal viral diseases have been documented in the Caribbean region since the 1940s, we found that studies on different animal viruses are limited, inconsistent, and scattered. Furthermore, a significant number of the reports were based on serological assays, yielding preliminary data. The available information was assessed to identify knowledge gaps and limitations, and accordingly, recommendations were made, with the overall goal to improve animal health and production, and combat zoonoses in the region. This article is protected by copyright. All rights reserved.

Detection and Molecular Characterization of Canine Alphacoronavirus in Free-Roaming Dogs, Bangladesh

Canine coronavirus (CCoV) is widespread among the dog population and causes gastrointestinal disorders, and even fatal cases. As the zoonotic transmission of viruses from animals to humans has become a worldwide concern nowadays, it is necessary to screen free-roaming dogs for their common pathogens due to their frequent interaction with humans. We conducted a cross-sectional study to detect and characterize the known and novel Corona, Filo, Flavi, and Paramyxoviruses in free-roaming dogs in Bangladesh. Between 2009-10 and 2016-17, we collected swab samples from 69 dogs from four districts of Bangladesh, tested using RT-PCR and sequenced. None of the samples were positive for Filo, Flavi, and Paramyxoviruses. Only three samples (4.3%; 95% CI: 0.9-12.2) tested positive for Canine Coronavirus (CCoV). The CCoV strains identified were branched with strains of genotype CCoV-II with distinct distances. They are closely related to CCoVs from the UK, China, and other CoVs isolated from different species, which suggests genetic recombination and interspecies transmission of CCoVs. These findings indicate that CCoV is circulating in dogs of Bangladesh. Hence, we recommend future studies on epidemiology and genetic characterization with full-genome sequencing of emerging coronaviruses in companion animals in Bangladesh.

Molecular Investigation of Canine Parvovirus-2 (CPV-2) Outbreak in Nevis Island: Analysis of the Nearly Complete Genomes of CPV-2 Strains from the Caribbean Region

To date, there is a dearth of information on canine parvovirus-2 (CPV-2) from the Caribbean region. During August–October 2020, the veterinary clinic on the Caribbean island of Nevis reported 64 household dogs with CPV-2-like clinical signs (hemorrhagic/non-hemorrhagic diarrhea and vomiting), of which 27 animals died. Rectal swabs/fecal samples were obtained from 43 dogs. A total of 39 of the 43 dogs tested positive for CPV-2 antigen and/or DNA, while 4 samples, negative for CPV-2 antigen, were not available for PCR. Among the 21 untested dogs, 15 had CPV-2 positive littermates. Analysis of the complete VP2 sequences of 32 strains identified new CPV-2a (CPV-2a with Ser297Ala in VP2) as the predominant CPV-2 on Nevis Island. Two nonsynonymous mutations, one rare (Asp373Asn) and the other uncommon (Ala262Thr), were observed in a few VP2 sequences. It was intriguing that new CPV-2a was associated with an outbreak of gastroenteritis on Nevis while found at low frequencies in sporadic cases of diarrhea on the neighboring island of St. Kitts. The nearly complete CPV-2 genomes (4 CPV-2 strains from St. Kitts and Nevis (SKN)) were reported for the first time from the Caribbean region. Eleven substitutions were found among the SKN genomes, which included nine synonymous substitutions, five of which have been rarely reported, and the two nonsynonymous substitutions. Phylogenetically, the SKN CPV-2 sequences formed a distinct cluster, with CPV-2b/USA/1998 strains constituting the nearest cluster. Our findings suggested that new CPV-2a is endemic in the region, with the potential to cause severe outbreaks, warranting further studies across the Caribbean Islands. Analysis of the SKN CPV-2 genomes corroborated the hypothesis that recurrent parallel evolution and reversion might play important roles in the evolution of CPV-2.

Diagnostic Challenges in Canine Parvovirus 2c in Vaccine Failure Cases

In this study, three different diagnostic tests for parvovirus were compared with vaccination status and parvovirus genotype in suspected canine parvovirus cases. Faecal samples from vaccinated (N17) and unvaccinated or unknown vaccination status (N41) dogs that had clinical signs of parvovirus infection were tested using three different assays of antigen tests, conventional and quantitative PCR tests. The genotype of each sample was determined by sequencing. In addition to the suspected parvovirus samples, 21 faecal samples from apparently healthy dogs were tested in three diagnostic tests to evaluate the sensitivity and specificity of the tests. The antigen test was positive in 41.2% of vaccinated dogs and 73.2% of unvaccinated diseased dogs. Conventional PCR and qPCR were positive for canine parvovirus (CPV) in 82.4% of vaccinated dogs and 92.7% of unvaccinated dogs. CPV type-2c (CPV-2c) was detected in 82.75% of dogs (12 vaccinated and 36 unvaccinated dogs), CPV-2b was detected in 5.17% dogs (one vaccinated and two unvaccinated) and CPV-2a in 1.72% vaccinated dog. Mean Ct values in qPCR for vaccinated dogs were higher than the unvaccinated dogs (p = 0.049), suggesting that vaccinated dogs shed less virus, even in clinical forms of CPV. CPV-2c was the dominant subtype infecting dogs in both vaccinated and unvaccinated cases. Faecal antigen testing failed to identify a substantial proportion of CPV-2c infected dogs, likely due to low sensitivity. The faecal samples from apparently healthy dogs (n = 21) showed negative results in all three tests. Negative CPV faecal antigen results should be viewed with caution until they are confirmed by molecular methods.

Molecular diversity of Alphacoronavirus 1 in dogs and cats in Colombia

Alphacoronavirus 1 (subgenus Tegacovirus, genus Alphacoronavirus, family Coronaviridae), which encompasses transmissible gastroenteritis virus (TGEV), feline coronavirus (FCoV) and canine coronavirus (CCoV), is an important pathogen that can cause severe gastroenteritis and is distributed worldwide. CCoV has two different genotypes: CCoV type I, which has a high identity with FCoV-I, and CCoV type II, which is divided into two subtypes, CCoV IIa (pantropic) and CCoV IIb, which is related to FCoV-II and has been involved in multiple recombination events. Between 2014 and 2018, 43 fecal samples from puppies and young dogs under 1 year of age with hemorrhagic enteritis and from 5 cats under 2 years of age with ascites or thoracic effusion were collected by a private veterinary practice in Bogotá, Colombia. A screening for Coronavirus via RT-PCR (nsp12) and PCR amplification of Canine protoparvovirus (VP1) revealed 27.1% (13/49) and 72.9% (35/49) positive samples, respectively. Positive samples for coronavirus were tested for M, N, S and the sequences grouped in the FCoV, CCoV-I and CCoV-IIb clusters that were distant from the pantropic type (IIa). The N gene formed two clusters, one exclusively with samples from this study in subtype II and another with strains in subtype I. For gene S (subtype I), the samples clustered with the Brazilian samples, while samples positive for S subtype IIb grouped into a cluster distinct from the other reference sequences. The prevalence of coronaviruses identified in this study is within the range reported by different countries worldwide.

First Molecular Identification of Canine Parvovirus Type 2 (CPV2) in Chile Reveals High Occurrence of CPV2c Antigenic Variant

Canine parvovirus type 2 (CPV2) is one of the most important intestinal pathogens in dogs and puppies. CPV2 has been evolved into three genetic and antigenic variants (2a, 2b, and 2c), which are distributed worldwide. We reported the first study of genetic diversity of CPV2 in Chile. Sixty-five samples were collected from puppies presenting with severe gastroenteritis and different vaccination statuses. PCR, restriction fragment length polymorphism (RFLP), and partial sequencing of the coding region of the structural viral protein VP2 was performed. Thirty of a total of 65 samples tested positive by PCR out of which 19 were further classified as CPV2c and one as CPV2a using RFLP and Sanger sequencing. The phylogeny was in concordance with the RFLP analysis. This is the first report of the genetic characterization of CPV2 in Chile and reveals a high occurrence of CPV2c.

An epidemiological investigation of porcine circovirus 3 infection in dogs in the Guangxi Province from 2015 to 2017, China

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This study was the first seroprevalence and genetic investigation of PCV3 in dogs in the Guangxi province, China.

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This work is the first in the world to obtain the complete genome of dog PCV3.

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These PCV3 strains from the Guangxi province help to determine that PCV3 from dog origin and pig origin are from different branches.

Porcine circovirus type 3 (PCV3) is an emerging circovirus species associated with several diseases. The study aimed to investigate the frequency of porcine circovirus 3 (PCV3) and its coinfection with canine parvovirus type 2 (CPV-2) in dogs in the Guangxi province from 2015 to 2017, China, and to examine the genome diversity of PCV3. Using polymerase chain reaction (PCR) amplification and sequencing, 96 of 406 (23.6%)samples were positive for PCV3, 38 out of 406 (9.4%) samples were coinfected with both PCV3 and CPV-2. The CPV-positive rate was significantly higher in the PCV3-positive samples than in the non-PCV3 samples, and the difference was extremely significant (P < 0.01). The complete genome (n=4) and ten capsid genes (n=10) of PCV3 were sequenced. Multiple sequence alignment results showed that these sequences shared 98.5–100% nucleotide similarity with the reference genome sequence and 97.5–100% nucleotide similarity with the reference capsid gene sequence. PCV3 was classified into two different genotypes, according to phylogenetic analysis based on the whole genome. These strains were clustered in PCV3a, showing a close relationship with PCV3-US/SD2016. Surprisingly, we separately analyzed these PCV3 strains from the Guangxi province and found that the dog and pig PCV3 are from different branches. In summary, this was the first seroprevalence and genetic investigation of PCV3 in dogs in the Guangxi province, China, and the first complete genome PCV3 from dogs obtained in the world. The results provide insights into the epidemiology and pathogenesis of this important virus.