Persistent infection of American bison (Bison bison) with bovine viral diarrhea virus and bosavirus.

Bovine viral diarrhea viruses (BVDV) are significant pathogens of cattle, leading to losses associated with reproductive failure, respiratory disease and immune dysregulation. While cattle are the reservoir for BVDV, a wide range of domestic and wild ruminants are susceptible to infection and disease caused by BVDV. Samples from four American bison (Bison bison) from a captive herd were submitted for diagnostic testing due to their general unthriftiness. Metagenomic sequencing on pooled nasal swabs and serum identified co-infection with a BVDV and a bovine bosavirus. The BVDV genome was more similar to the vaccine strain Oregon C24 V than to other BVDV sequences in GenBank, with 92.7 % nucleotide identity in the open reading frame. The conserved 5'-untranslated region was 96.3 % identical to Oregon C24 V. Bosavirus has been previously identified in pooled fetal bovine serum but its clinical significance is unknown. Sequencing results were confirmed by virus isolation and PCR detection of both viruses in serum and nasal swab samples from two of the four bison. One animal was co-infected with both BVDV and bosavirus while separate individuals were positive solely for BVDV or bosavirus. Serum and nasal swabs from these same animals collected 51 days later remained positive for BVDV and bosavirus. These results suggest that both viruses can persistently infect bison. While the etiological significance of bosavirus infection is unknown, the ability of BVDV to persistently infect bison has implications for BVDV control and eradication programs. Possible synergy between BVDV and bosavirus persistent infection warrants further study.

Seroprevalence of viral and vector-borne bacterial pathogens in domestic dogs (Canis familiaris) in northern Botswana.

BACKGROUND: Domestic dogs (Canis familiaris) have the potential to act as disease reservoirs for wildlife and are important sentinels for common circulating pathogens. Therefore, the infectious disease seroprevalence among domestic dogs in northern Botswana may be indicative of pathogen exposure of various wildlife species. The objective of this study was to assess the seroprevalence of Ehrlichia spp., Borrelia burgdorferi, Anaplasma spp., Dirofilaria immitis, canine adenovirus, canine parvovirus, and canine distemper virus in domestic dogs as proxies of disease prevalence in the local wildlife in the Okavango Delta region of Botswana. Statistical analysis assessed crude and factor-specific seroprevalence proportions in relation to age, sex, and geographical location as predictors of seropositivity. Logistic regression was used to identify adjusted predictors of seropositivity for each of the pathogens of interest. RESULTS: Samples from 233 dogs in a total of seven locations in Maun, Botswana, and surrounding villages were collected and serologically analyzed. No dogs were seropositive for B. burgdorferi, while low seroprevalence proportions were observed for Anaplasma spp. (2.2%) and D. immitis (0.9%). Higher seroprevalence proportions were observed for the tick-borne pathogen Ehrlichia spp. (21.0%), and 19.7% were seropositive for canine adenovirus (hepatitis). The highest seroprevalence proportions were for canine parvovirus (70.0%) and canine distemper virus (44.8%). The predictors of seropositivity revealed that adults were more likely to be seropositive for canine adenovirus, canine distemper virus, and canine parvovirus than juveniles, and location was a risk factor for canine adenovirus, canine distemper virus, canine parvovirus, and Ehrlichia spp. CONCLUSIONS: Results indicate that increasing tick control and vaccination campaigns for domestic dogs may improve the health of domestic animals, and potentially wildlife and humans in the Okavango Delta since viral and vector-borne bacterial pathogens can be transmitted between them.

Intestinal Microbial Dysbiosis in Beagles Naturally Infected with Canine Parvovirus.

Canine parvoviral enteritis (PVE) is an important intestinal disease of the puppies; however, the potential impact of the canine parvovirus (CPV) on the gut microbiota has not been investigated. Therefore, the aim of this study was to evaluate the gut microbial shifts in puppies naturally infected with CPV. Fecal samples were collected from healthy dogs and those diagnosed with PVE at 4, 6, 8, and 12 weeks of age. The distal gut microbiota of dogs was characterized using Illumina MiSeq sequencing of the bacterial 16S rRNA genes. The sequence data were analyzed using QIIME with an Operational Taxonomic Unit definition at a similarity cutoff of 97%. Our results showed that the CPV was associated with significant microbial dysbiosis of the intestinal microbiota. Alpha diversity and species richness and evenness in dogs with PVE decreased compared to those of healthy dogs. At the phylum level, the proportion of Proteobacteria was significantly enriched in dogs with PVE while Bacteroidetes was significantly more abundant in healthy dogs (p < 0.05). In dogs with PVE, Enterobacteriaceae was the most abundant bacterial family accounting for 36.44% of the total bacterial population compared to only 0.21% in healthy puppies. The two most abundant genera in healthy dogs were Prevotella and Lactobacillus and their abundance was significantly higher compared to that of dogs with PVE (p < 0.05). These observations suggest that disturbances of gut microbial communities were associated with PVE in young dogs. Evaluation of the roles of these bacterial groups in the pathophysiology of PVE warrants further studies.

Fecal microbiota transplantation in puppies with canine parvovirus infection.

BACKGROUND: Diarrhea associated with parvovirus infection is common in dogs. Supportive care is the mainstay of treatment, but recovery may be prolonged and mortality rate can be high. Modification of the intestinal bacterial microbiota has been promising in human and veterinary medicine as an adjunctive treatment of various enteric diseases. OBJECTIVES: To investigate the safety and efficacy of fecal microbiota transplantation (FMT) on the clinical recovery of puppies with acute hemorrhagic diarrhea syndrome. ANIMALS: Sixty-six puppies with parvovirus infection were evaluated at 2 veterinary hospitals. METHODS: Randomized clinical trial. Puppies were randomly distributed into 2 groups: standard treatment (STD) and standard treatment + FMT (STD + FMT). The STD puppies (n = 33) received only treatment with IV fluids and antimicrobials and the STD + FMT puppies (n = 33) received FMT in addition to standard treatment. For FMT, 10 g of feces from a healthy dog diluted in 10 mL of saline were administered rectally 6-12 hours post-admission. RESULTS: Among survivors, treatment with FMT was associated with faster resolution of diarrhea (P < .001) and shorter hospitalization time (P = .001; median, 3 days in STD + FMT; median, 6 days in STD) compared to standard treatment. Mortality in STD was 36.4% (12/33) as compared to 21.2% (7/33) in puppies treated with FMT, but there was no statistical difference between groups (P = .174). Polymerase chain reaction indicated that all animals carried canine parvovirus, strain CPV-2b. CONCLUSIONS: Fecal microbiota transplantation in parvovirus-infected puppies was associated with faster resolution of diarrhea.

Microbiological profile of adenoid hypertrophy correlates to clinical diagnosis in children.

OBJECTIVE: Adenoid hypertrophy is a common condition in childhood, which may be associated with recurring acute otitis media (RAOM), otitis media with effusion (OME), and obstructive sleep apnea syndrome (OSAS). These different clinical characteristics have some clinical overlap; however, they might be explained by distinct immunologic and infectious profiles and result in various histopathologic findings of adenoid specimens. METHODS: A total of 59 children with adenoid hypertrophy undergoing adenoidectomy were studied. Three series of identical adenoid specimens were processed to hematoxylin-eosin (H.E.) and Gram staining and to respiratory virus specific real-time PCR, respectively. RESULTS: According to the clinical characteristics, patients were recruited into three groups: RAOM (n = 25), OME (n = 19), and OSAS (n = 15). Bacterial biofilms were detected in 21 cases, while at least one of the studied respiratory viruses was detected in 52 specimens. RAOM cases were significantly associated with biofilm existence (n = 20, P < 0.001). In contrast, OME group was characterized by the absence of bacterial biofilm and by normal mucosa. Showing a statistically significant correlation, all OME cases were positive for human bocavirus (HBoV, P < 0.001). CONCLUSIONS: Bacterial biofilms might contribute to the damage of respiratory epithelium and recurring acute infections resulting in RAOM. In OME cases persisting respiratory viruses, mainly HBoV, can cause subsequent lymphoid hyperplasia leading to ventilation disorders and impaired immunoreactivity of the middle ear cleft.

Co-infection of human parvovirus B19 with Plasmodium falciparum contributes to malaria disease severity in Gabonese patients.

BACKGROUND: High seroprevalence of parvovirus B19 (B19V) coinfection with Plasmodium falciparum has been previously reported. However, the impact of B19V-infection on the clinical course of malaria is still elusive. In this study, we investigated the prevalence and clinical significance of B19V co-infection in Gabonese children with malaria. METHODS: B19V prevalence was analyzed in serum samples of 197 Gabonese children with P. falciparum malaria and 85 healthy controls using polymerase chain reaction (PCR), enzyme-linked immunosorbent assay (ELISA), and direct DNA-sequencing. RESULTS: B19V was detected in 29/282 (10.28%) of Gabonese children. B19V was observed more frequently in P. falciparum malaria patients (14.21%) in comparison to healthy individuals (1.17%) (P<0.001). Notably, the mild-malaria group revealed significantly lower hematocrit levels in B19V/P. falciparum co-infection than in P. falciparum mono-infection (P<0.05). Genetic analysis revealed a predominance of B19V genotype-1 (71.43%) in the studied population. However, B19V-genotype 2 was observed significantly more often in children with severe-malaria than in mild-malaria (P=0.04). CONCLUSION: Our findings reveal that B19V-infection is frequent in Gabonese children with P. falciparum malaria and signifies a possible contribution of B19V on the clinical course of malaria in a genotype-dependent manner. B19V co-infection should be considered as a additional diagnostic measure in malaria patients with life threatening anemia.

Molecular evolutionary genetic analysis of emerging parvoviruses identified in pigs.

Parvoviruses infect a wide variety of vertebrates and arthropods and are associated with various clinical manifestations. Due to the advent of new sequence-independent PCR methods and high-throughput sequencing, several novel members of parvoviruses within the subfamily Parvovirinae were recently described. Several of these viruses do not fit in the current classification and others now have confusing or contradictory nomenclature because two or more names were used for similar or identical groups of parvoviruses or identical names were used for distinct virus groups. In this study, recently described vertebrate parvoviruses with emphasis on those identified in pigs were classified through phylogenetic analyses based on the sequences of their complete or near complete genomes, open reading frame (ORF) 1 (non-structural protein, NS1), ORF2 (capsid protein, VP1), and ORF3 (nuclear phosphoprotein, NP1) genes by using Bayesian Markov chain Monte Carlo (MCMC), Maximum Likelihood (ML) and Neighbor-Joining (NJ) methods. Among all available vertebrate parvovirus sequences, eight distinct clades were identified, corresponding to the five well established genera Parvovirus, Erythrovirus, Denpendovirus, Amdovirus and Bocavirus. Moreover, three novel clades were identified and tentatively designated as PARV4-like virus, novel clade 1 and novel clade 2. Parvoviruses in pigs were found to be distributed across four different clades including Parvovirus, Bocavirus, PARV4-like virus and the novel clade 2. All pig parvoviruses identified to date were organized based on the current analysis. The present analysis will assist to clarify the nomenclature of parvoviruses in pigs and facilitate future uniform assignment of names for new parvoviruses within the subfamily Parvovirinae.

Detection, prevalence and analysis of emerging porcine parvovirus infections.

A number of newly identified porcine parvoviruses had been described during the last decade, but the presence and prevalence of these viruses are unknown in Hungary and only partly known for Europe. The present study was conducted to detect and measure the prevalence of these viruses, namely porcine parvovirus (PPV) 2, PPV3, PPV4, porcine bocavirus (PBoV) 1, PBoV2, PBo-likeV and the 6V and 7V parvoviruses. The prevalence of PPV1 and porcine circovirus type 2 (PCV2) was also investigated. Faecal samples, blood serum samples, organ tissues, foetuses and semen were collected from different swine herds in Hungary and tested by polymerase chain reaction methods specific for the different viruses. The results indicated that all of the examined parvoviruses were present in Hungary, hence in Europe. The prevalence was 18.1% for PCV2, 0.5 % for PPV1, 6.4% for PPV2, 9.7% for PPV3, 6.4% for PPV4, 1.5% for PBo-likeV, 4.8% for PBoV1 and PBoV2 and 1.8% for 6V and 7V. Based on the analysis of partial PPV4 and PBo-likeV sequences, these viruses showed a high degree of sequence conservation, whereas PPV3 and the majority of PPV2, PBoV1, PBoV2, 6V and 7V sequences showed higher variability. Possible sites of recombination were also identified between PBoV1 and PBoV2 genomes.

Canine parvovirus type 2c infection in a kitten associated with intracranial abscess and convulsions.

A case of canine parvovirus type 2c (CPV-2c) infection in a 3-month-old feral kitten with a cerebral abscess and neurological disease is reported. The cat displayed ataxia and convulsions together with signs of gastroenteritis and profound alteration of the total and differential white blood cell counts. A parvovirus strain was detected by a TaqMan assay in the blood and faeces of the affected kitten, which was characterised as CPV by means of molecular assays but did not react with any of the CPV type-specific probes. By sequence and phylogenetic analyses of the VP2-protein gene, the CPV-2c strain displayed a non-coding mutation in the probe-binding region. Although the role of CPV-2c in this particular case is unclear, it is possible that it predisposed the kitten to the clinical signs seen. Continuous surveillance is needed to monitor future spreading of this CPV-2c mutant, and any associated clinical signs, in the dog and cat population.

Tako-Tsubo cardiomyopathy (apical ballooning) with parvovirus B19 genome in endomyocardial biopsy.

The phenomenon of transient apical ballooning is a rare underlying cause of severe left ventricular dysfunction and has been described as Tako-Tsubo-like cardiomyopathy. Acute myocarditis has been reported to masquerade as acute myocardial infarction or vice versa and is considered as differential diagnosis in this phenomenon. We present here a case of an adult female who was admitted to our cardiology department with chest pain, electrocardiographic and echocardiographic features, suggestive of an acute anterior myocardial infarction, preceded by physical and emotional stress. Coronary angiography demonstrated coronary arteries without relevant atherosclerotic lesions; left ventriculography showed a severe anteroapical dysfunction. Right ventricular endomyocardial biopsy showed normal cardiac tissue, but was positive for Parvovirus B19. Follow-up (2 months later) showed complete regression of regional wall motion abnormalities in transthoracic echocardiography.

Serologic and molecular detection of human Parvovirus B19 infection.

Following its identification by Yvonne Cossart in 1975, human Parvovirus B19 has been recognized as the causative agent of a wide range of diseases. In childhood, the most common disease is a typical exanthema called "fifth disease". In adults, viral infection may be responsible for fetal loss and for aplastic anaemia in immuno-compromised patients. Because persistent viral infection may induce an autoimmune response, Parvovirus B19 is emerging as an environmental factor linked to the pathogenesis of autoimmunity. As a result of its expanding disease spectrum, Parvovirus B19 is the subject of intense efforts to clarify the pathogenesis of virus-related disorders as well as improve diagnostic laboratory testing including standardization of serological and nucleic acid-based detection assays. Enzymatic immunoassays based on conformational antigens have proven to be the most important tools for accurate diagnosis in the majority of cases. In other selected clinical cases, the detection of Parvovirus B19 infection can be complemented by PCR and, more recently, by the real-time PCR.

Human parvovirus B19 experimental infection in human fibroblasts and endothelial cells cultures.

With the aim to detect what kind of cells, in addition to erythroid progenitors, could be involved in the pathogenesis of B19 infection in some connective tissue diseases, primary cultures of human fibroblasts (HF) and endothelial cells (HUVEC) were exposed to a B19 positive serum (350 genome copies/cell). The presence of NS1 and VP1 mRNA, in both HF and HUVEC cultures 1, 2 and 6 days after the exposure, indicated infection by B19 virus. However, no significant increase of B19 DNA level in the infected HF and HUVEC cultures was detectable through the entire incubation period of 6 days. It is possible that HF and HUVEC are not permissive for B19 virus replication or, alternatively, that few cells only get infected by B19 virus. HF and HUVEC stimulation with different growth factors or cytokines could be required for a B19 productive infection to occur.

Experimental infection of cynomolgus monkeys with simian parvovirus.

Simian parvovirus is a recently discovered parvovirus that was first isolated from cynomolgus monkeys. It is similar to human B19 parvovirus in terms of virus genome, tropism for erythroid cells, and characteristic pathology in natural infections. Cynomolgus monkeys were infected with simian parvovirus to investigate their potential usefulness as an animal model of human B19 parvovirus. Six adult female cynomolgus monkeys were inoculated with purified simian parvovirus by the intravenous or intranasal route and monitored for evidence of clinical abnormalities; this included the preparation of complete hematological profiles. Viremia and simian parvovirus-specific antibody were determined in infected monkeys by dot blot and Western blot assays, respectively. Bone marrow was examined at necropsy 6, 10, or 15 days postinfection. All of the monkeys developed a smoldering, low-grade viremia that peaked approximately 10 to 12 days after inoculation. Peak viremia coincided with the appearance of specific antibody and was followed by sudden clearance of the virus and complete, but transient, absence of reticulocytes from the peripheral blood. Clinical signs were mild and involved mainly anorexia and slight weight loss. Infection was associated with a mild decrease in hemoglobin, hematocrit, and erythrocyte numbers. Bone marrow showed marked destruction of erythroid cells coincident with peak viremia. Our findings indicate that infection of healthy monkeys by simian parvovirus is self-limited and mild, with transient cessation of erythropoiesis. Our study has reproduced Koch's postulates and further shown that simian parvovirus infection of monkeys is almost identical to human B19 parvovirus infection of humans. Accordingly, this animal model may prove valuable in the study of the pathogenesis of B19 virus infection.

Detection of H-1 parvovirus and Kilham rat virus by PCR.

H-1 virus and Kilham rat virus (KRV) are autonomous parvoviruses which generally cause subclinical infections in rats and can cause persistent infections in cell cultures. In this study, primer sets specific for either H-1 or KRV were designed on the basis of DNA sequence comparisons of the rodent parvoviruses. The specificities of the H-1 and KRV-specific primer sets were determined by testing viral preparations of seven different parvoviruses and nine other viruses known to infect rodents. The H-1-specific PCR assay amplified the expected 254-bp product only in the presence of H-1 viral DNA and was able to detect as little as 100 fg of H-1 viral DNA. The KRV-specific PCR assay generated the expected 281-bp product only when KRV viral DNA was used as the template and was able to detect as little as 10 pg of KRV viral DNA. Each assay was able to detect its respective virus in tissues from rats experimentally infected with H-1 or KRV. In contrast, no product was amplified by either assay with tissues from mock-infected rats. Our findings indicate that these PCR assays provide rapid, specific, and sensitive methods for the detection of H-1 or KRV infection in rats and cell culture systems.

[Subacute thyroiditis in Parvovirus B19 infection]. / Subakut thyreoiditis ved Parvovirus B19-infektion.

In a 32-year-old women with clinical and scintigraphic signs of thyroiditis, serological screening showed positive IgG and IgM titres against Parvovirus B19 (PB19). Subacute thyroiditis has not previously been reported following PB19 infection. The present case suggests that subacute thyroiditis may be caused by PB19 infection. Further screening is necessary to establish whether this infection is more frequently associated with subacute thyroiditis than previously thought.

Characterization of the feline host range and a specific epitope of feline panleukopenia virus.

The feline parvovirus subgroup is comprised of viruses isolated from various carnivores, including the dog, cat, mink, raccoon, Arctic fox, and raccoon dog. Those viruses are > 98% identical in their DNA sequences and are very similar antigenically. We have shown that although canine parvovirus (CPV) replicates in numerous feline cell lines in vitro it does not infect cats after parenteral inoculation (U. Truyen and C. R. Parrish, (1992) J. Virol. 66, 5399-5408). Here we use recombination mapping to locate some viral determinants required for feline host range, and show that the ability to replicate in cats was determined by the right-hand 45% of the genome, most likely a function of the capsid protein gene. Efficient replication in the cat appeared to require feline panleukopenia virus sequences from both ends of the VP2 molecule, which contained differences of VP2 amino acid residues 80, 564, and 568. The difference at amino acid 80 was also associated with expression of an FPV-specific antigenic epitope. The differences which affected the feline host range were located in a region of the capsid structure where three VP2 molecules interact, and the mutations gave rise to changes in the conformation of loops of the three adjoining VP2 monomers. The mechanism(s) of the in vivo feline host range restriction were not defined, and we were unable to show in vitro inhibition of virus infectivity by feline serum components or erythrocytes.

Minute virus of canines (MVC, canine parvovirus type-1): pathogenicity for pups and seroprevalence estimate.

Minute virus of canines (MVC, canine parvovirus type-1) caused inapparent to severe illness in neonatal specific-pathogen-free pups exposed by the oronasal route. The experimental disease was generally mild. Four of 21 infected pups had clinical signs of respiratory illness, but only 2 pups, not euthanized during the early postinoculation period, developed severe illness or died. Principal pathologic changes included bronchitis and interstitial pneumonia with various degrees of lymphadenitis. In contrast to the reported field cases, enteric signs were absent in the experimentally infected animals. Histopathologic changes in the small intestine were mild or absent. Bronchial, bronchiolar, and alveolar epithelial cells appeared to be the sites of initial and most extensive viral growth, reflecting the pattern of histopathologic changes. The disease caused by MVC was mild in comparison to that caused by canine parvovirus-type 2. MVC now appears to be established as a cause of illness in young pups and of transplacental infections with embryo resorption. The prevalence of MVC hemagglutination-inhibiting antibodies was high (approximately 50%) in adult dog sera from widely separated geographic areas of the United States.