Molecular Epidemiology and Genetic Evolution of Canine Parvovirus Type 2 in Diarrheic Dogs in Serbia From 2008 To 2020

Canine Parvovirus 2 (CPV2) is a causal agent of an infectious disease with the highest fatality rate among dogs. However, in Serbia, it has never been investigated thoroughly. This study was conducted on samples originating from dogs with diarrhea in anamnesis, stored in the sample bank, submitted for various reasons to the Institute of Veterinary Medicine of Serbia. In total, 50 rectal swab samples were collected from the period 2008 to 2020, and consequently tested. Out of 50 rectal swab samples, the CPV2 genome was detected in 14 (28%). This retrospective study showed the presence of three different variants of CPV2 in diarrheic dogs during the last 12 years in Serbia. CPV2a was the most prevalent variant (60%) followed by CPV2b (30%), and CPV2c (10%). Interestingly, CPV2a had been the predominantly detected variant up until 2018. Nevertheless in 2019, there was the first detected occurrence of the CPV2b variant, followed by the first detection of the CPV2c in 2020. This study reports the evidence and distribution of CPV2 throughout the time-lapse from 2008 to 2020, providing new information about the presence and the prevalence of virus strains in Serbia.

Current trends of canine parvoviral enteritis: Nigeria perspective

Background: Canine parvoviral enteritis (CPE) is currently considered one of the major leading causes of morbidity and mortality in dogs. Canine parvovirus (CPV-2) was first isolated in 1978, ever since then the virus has mutated to CPV-2a, CPV-2b and recently CPV-2c, which has made the control and eradication of disease seemingly impossible. The disease has been reported in several parts of the world including; USA, Canada, Australia, United Kingdom, Taiwan, and Tunisia, South Africa and Nigeria. The identification of the strains of CPV-2 that are currently circulating in the canine population is very essential for the understanding of viral evolution and the development of measures to control its spread. This review therefore, focuses on the current trends and antigenic variants of canine parvovirus type 2 (CPV-2) circulating in Nigeria. Methods: Previous literatures were reviewed on the status of canine parvovirus type 2 in Nigeria. The emphasis was on the antigenic variants of CPV-2 circulating in Nigeria and strains of the virus in the vaccines, and out breaks of infections. Results: Control and prevention of canine parvoviral enteritis (CPE) has remained a global challenge, and relies mainly on extensive vaccination. Sequence analysis of CPV-2 has revealed the presence of the three antigenic variants in Nigeria. CPV-2c is now predominantly in Nigeria and as such with so many countries of the world, without corresponding vaccines with the variants. Hence understanding the antigenic variants of CPV-2 virus circulating within a geographical area is very essential in controlling the infection. Conclusion: CPE infection is endemic in Nigeria and mainly infects dogs less than six months of age. The disease is of serious socio-economic importance to dog owners and breeders, as a number one killer disease of dogs. The three stains of the canine parvovirus type 2, (2a, 2b and 2c) exists in Nigeria, with predominantly 2c. The current vaccines mainly used in Nigeria are original CPV-2, 2a or 2b, and do not protect dogs against CPE due to 2c infections. We therefore, recommend that 2c be incorporated in CPV-2 vaccines presently used in Nigeria

Phylogenetic Characteristics of Canine Parvovirus Type 2c Variant Endemic in Shanghai, China

Canine parvovirus type 2 (CPV-2) has spread and mutated globally over the past 40 years. In the present study, 206 samples from dogs suspected of CPV-2 infection were collected from five veterinary clinics in Shanghai city, China. The average positive rate for CPV-2 was detected to be 40.78% using the PCR method. Using an F81 cell (feline kidney cell) culture, the isolates of three CPV-2c strains were obtained. The near full-length genome sequences of the isolates were determined and submitted to GenBank: CPV-SH2001 (MW650830), CPV-SH2002 (MW811188), and CPV-SH2003 (MW811189). By comparing the amino acid sequences of 12 CPV strains with those of 48 related strains retrieved from GenBank, all of the CPV strains from Shanghai were typed as belonging to a relatively new CPV-2c variant spreading in Asia, with typical amino acid residues (5Gly, 267Tyr, 324Ile, and 370Arg) in the VP2 protein. The divergence time of this new CPV-2c clade was estimated by the phylogenetic tree using the maximum likelihood and RelTime with Dated Tips (RTDT) approaches. Our results indicate that the 426 and 324 VP2 amino acid residues are under strong selection pressure with a posterior probability of 0.966 and 0.943, respectively. Therefore, this study provides insight into the phylogenetic characteristics of the current CPV-2c variant in Shanghai city, China.

Retrospective Genotyping and Whole Genome Sequencing of a Canine Parvovirus Outbreak in Bangladesh

Canine parvovirus 2 (CPV-2) outbreaks in close quarters such as kennels or shelters can cause substantial case fatality. Thirteen dead Labradors from a secluded kennel of security dogs presented with typical clinical signs and gross pathology of parvovirus infection. Whole genome shotgun sequencing from tissue-extracted genomic DNA detected new CPV-2a as the contributing antigenic variant. Further genotyping using polymerase chain reaction coupled with high-resolution melt assays (PCR-HRM) confirmed new CPV-2a infection in all deceased dogs. PCR-HRM of additional thirty-four clinically suspected dogs suggested that this variant is in wider community circulation, at least in the southeastern part of Bangladesh. We present complete genome sequence of the new CPV-2a variant circulating in the domestic canine population of Bangladesh.

Comparison of Eight Commercially Available Faecal Point-of-Care Tests for Detection of Canine Parvovirus Antigen

A real-time polymerase chain reaction (qPCR) is considered the gold standard for the laboratory diagnosis of canine parvovirus (CPV) infection but can only be performed in specialized laboratories. Several point-of-care tests (POCT), detecting CPV antigens in faeces within minutes, are commercially available. The aim of this study was to evaluate eight POCT in comparison with qPCR. Faecal samples of 150 dogs from three groups (H: 50 client-owned, healthy dogs, not vaccinated within the last four weeks; S: 50 shelter dogs, healthy, not vaccinated within the last four weeks; p = 50 dogs with clinical signs of CPV infection) were tested with eight POCT and qPCR. Practicability, sensitivity, specificity, positive (PPV) and negative predictive values (NPV), as well as overall accuracy were determined. To assess the differences between and agreement among POCT, McNemar’s test and Cohen’s Kappa statistic were performed. Specificity and PPV were 100.0% in all POCT. Sensitivity varied from 22.9–34.3% overall and from 32.7–49.0% in group P. VetexpertRapidTestCPVAg® had the highest sensitivity (34.3% overall, 49.0% group P) and differed significantly from the 3 POCT with the lowest sensitivities (Fassisi®Parvo (27.7% overall, 36.7% group P), Primagnost®ParvoH+K (24.3% overall, 34.7% group P), FASTest®PARVOCard (22.9% overall, 32.7% group P)). The agreement among all POCT was at least substantial (kappa >0.80). A positive POCT result confirmed the infection with CPV in unvaccinated dogs, whereas a negative POCT result did not definitely exclude CPV infection due to the low sensitivity of all POCT.

Increased survival in puppies affected by Canine Parvovirus type II using an immunomodulator as a therapeutic aid

Canine parvovirus type II (CPV-2) infection induces canine parvoviral enteritis (CPE), which in turn promotes sepsis and systemic inflammatory response syndrome (SIRS). Mortality in this disease is usually registered within 48–72 h post-hospitalization, the critical period of the illness. It has been recently described that the use of an immunomodulator, whose major component is monomeric ubiquitin (mUb) without the last two glycine residues (Ub∆GG), in pediatric human patients with sepsis augments survival. It is known that CXCR4 is the cell receptor of extracellular ubiquitin in humans. This work aimed to explore the effect of one immunomodulator (human Dialyzable Leukocyte Extract-hDLE) as a therapeutic auxiliary in puppies with sepsis and SIRS induced by CPE. We studied two groups of puppies with CPV-2 infection confirmed by polymerase chain reaction. The first group received conventional treatment (CT) and vehicle (V), while the second group received CT plus the immunomodulator (I). We assessed both groups' survival, clinical condition, number of erythrocytes, neutrophils, and lymphocytes during the hospitalization period. In addition, hematocrit, hemoglobin, plasma proteins and cortisol values, as well as norepinephrine/epinephrine and serotonin concentration were determined. Puppies treated with CT + I showed 81% survival, mild clinical signs, and a significant decrease in circulating neutrophils and lymphocytes in the critical period of the treatment. In contrast, the CT + V group presented a survival of 42%, severe clinical status, and no improvement of the parameters evaluated in the critical period of the disease. We determined in silico that human Ub∆GG can bind to dog CXCR4. In conclusion, the administration of a human immunomodulator (0.5 mg/day × 5 days) to puppies with CPE under six months of age reduces the severity of clinical signs, increases survival, and modulates inflammatory cell parameters. Further studies are necessary to take full advantage of these clinical findings, which might be mediated by the human Ub∆GG to canine CXCR4 interaction.