Prevalence of canine herpesvirus 1 and associated risk factors among bitches in Iranian breeding kennels and farms.

BACKGROUND: Canine herpesvirus 1 (CHV-1) is an important cause of death in newborn puppies and of fertility problems in adult dogs. Identification of risk factors may help to reduce infection rates and alleviate concerns for dog owners and breeders. This study was designed to screen for CHV-1 infection in bitches of breeding kennels and farms in Iran and relate this to possible risk factors. METHODS: A total of 63 vaginal samples were collected from dogs in 5 breeding kennels (n = 47) and from 7 farms (n = 16). Real-time polymerase chain reaction was used to detect the CHV-1 specific glycoprotein B (gB) gene. Prevalence rates were evaluated in relation to various risk factors, including region, housing, vaccination, deworming, pregnancy, reproductive problems, number of dogs living together and hygiene conditions. RESULTS: In total, 21 (33.3%) of 63 vaginal samples were positive for CHV-1 DNA. The prevalence rate in farms (7/16; 43.7%) was higher than in kennels (14/47; 29.7%). No association was found between CHV-1 prevalence and potential risk factors. CONCLUSIONS: CHV-1 is highly prevalent in dogs in Iranian farms and kennels. Since the CHV1 vaccine is unlicensed in Iran, effective management strategies are essential to reduce the consequences of this pathogen.

Filling the Gap in Southern Europe-Diversity of Cryphonectria parasitica and Associated Mycovirus (Cryphonectria hypovirus 1) in Montenegro.

Cryphonectria parasitica is an invasive fungal pathogen that causes blight disease on chestnut trees. Its destructive effect can be controlled with naturally occurring mycovirus Cryphonectria hypovirus 1 (CHV1). To date, the spread of C. parasitica and CHV1 in Europe is fairly well documented, but there are still several unexplored regions. Thus, we sampled blight cankers from four sweet chestnut populations in Bay of Kotor and Lake Skadar regions in Montenegro. We determined vegetative compatibility (vc) type and mating-type diversity using molecular vic and MAT1 genotyping, as well as confirming the presence of CHV1 by RT-PCR. We identified 11 vc types, with EU-12 being the dominant one represented by 58.2% of all fungal isolates. The Shannon diversity index ranged from 0.93 to 1.47. Both mating types of C. parasitica were found in all four populations. The prevalence of CHV1 ranged from 15% to 40%. All CHV1 isolates belonged to Italian subtype I of CHV1 and were closely related, with relatively recent common ancestors. Our results indicate a longer presence of C. parasitica and CHV1 in Montenegro than previously thought. Natural biocontrol with CHV1 seems to be well established. However, it has the potential for deterioration; thus, close monitoring is required.

Phylogenomic Analysis of Global Isolates of Canid Alphaherpesvirus 1.

Canid alphaherpesvirus 1 (CHV-1) is a widespread pathogen of dogs with multiple associated clinical signs. There has been limited prior investigation into the genomics and phylogeny of this virus using whole viral genome analysis. Fifteen CHV-1 isolates were collected from animals with ocular disease based in the USA. Viral DNA was extracted for Illumina MiSeq full genome sequencing from each isolate. These data were combined with genomes of previously sequenced CHV-1 isolates obtained from hosts in the UK, Australia and Brazil. Genomic, recombinational and phylogenetic analysis were performed using multiple programs. Two isolates were separated into a clade apart from the remaining isolates and accounted for the majority of genomic distance (0.09%): one was obtained in 2019 from a USA-based host (ELAL-1) and the other in 2012 from a host in Brazil (BTU-1). ELAL-1 was found to contain variants previously reported in BTU-1 but also novel variants in the V57 gene region. Multiple non-synonymous variants were found in USA-based isolates in regions associated with antiviral resistance. Evidence of recombination was detected between ELAL-1 and BTU-1. Collectively, this represents evidence of trans-boundary transmission of a novel form of CHV-1, which highlights the importance of surveillance for this pathogen in domestic dog populations.

First molecular study of Canine herpesvirus-1 in reproductive specimens of adult dogs in southeast of Iran.

Canine herpesvirus-1 (CHV-1) is recognized to be enzootic in the dog population with a widespread distribution. This pathogen leads to a lethal generalized illness in newborn puppies and is associated with reproductive disorders. CHV-1 should be considered as an important pathogen of neonatal death and infertility; so, it appears to pose a threat for breeding kennels. Although serologic data point to the circulation of CHV-1 among dogs of Iran are available, no definitive diagnosis has been conducted based on the molecular assay. So, this research was done to detect the prevalence of CHV-1 in dogs of Kerman. In this study, the presence of CHV-1 in vaginal specimens and biopsies of the uterus of dogs referring to the Veterinary Hospital of Shahid Bahonar University of Kerman was determined. Fifteen uterine samples and seven vaginal samples were included in group of the pregnant dogs. Moreover, thirteen uterine samples and twenty vaginal samples were related to the dogs displaying suspicious clinical signs such as reproductive disorders. Samples were collected and evaluated using real-time PCR. Viral DNA was detected in 21 samples from a total of 140 (15 %) collected samples which were related to 14 uterine samples (20 %) and 7 (10 %) vaginal specimens. The association of this virus with age, breed, housing, pregnancy and reproductive disorders was not significant. Five positive reproductive samples were belonged to the dogs with a history of reproductive disorders including pyometra, metritis, stillbirths, vaginitis and vaginal prolapse. This study is the first molecular detection of CHV-1 in reproductive samples of dogs in Iran. Considering the significant prevalence of this virus, it is necessary to carry out management measures in controlling and preventing this disease. Tracing CHV-1 requires further research on this virus in dogs of this region.

Molecular evolution and invasion pattern of Cryphonectria hypovirus 1 in Europe: Mutation rate, and selection pressure differ between genome domains.

Understanding virus evolution is a fundamental goal of virology, evolutionary biology, and disease epidemiology. We provide a detailed analysis of evolution and origin of Cryphonectria hypovirus 1 (CHV1) populations in Europe, based on the complete genome sequence of all European subtypes. Phylogenetic analyses divided European strains into two closely related clades. Strains of the subtype I belong to the first, while strains of the subtypes F1, D and E belong to the second clade suggesting that the subtypes F1, D and E are more closely related than previously thought. Strains of the subtype F2 appeared to be recombinant; subtypes F1/D/E contributed a larger fraction of sequence while subtype I contributed a smaller fraction. The p29 was the most variable domain, while the replication-associated large ORF B protein was the most conserved domain within the CHV1. Low sequence similarity, predominant negative selection and frequent recombination characterise the evolution of CHV1.

New Paradigms for the Study of Ocular Alphaherpesvirus Infections: Insights into the Use of Non-Traditional Host Model Systems.

Ocular herpesviruses, most notably human alphaherpesvirus 1 (HSV-1), canid alphaherpesvirus 1 (CHV-1) and felid alphaherpesvirus 1 (FHV-1), infect and cause severe disease that may lead to blindness. CHV-1 and FHV-1 have a pathogenesis and induce clinical disease in their hosts that is similar to HSV-1 ocular infections in humans, suggesting that infection of dogs and cats with CHV-1 and FHV-1, respectively, can be used as a comparative natural host model of herpesvirus-induced ocular disease. In this review, we discuss both strengths and limitations of the various available model systems to study ocular herpesvirus infection, with a focus on the use of these non-traditional virus-natural host models. Recent work has demonstrated the robustness and reproducibility of experimental ocular herpesvirus infections in dogs and cats, and, therefore, these non-traditional models can provide additional insights into the pathogenesis of ocular herpesvirus infections.

Canid herpesvirus 1 (CHV-1)-related disease in older puppies and CHV-1 shedding in the vagina of adult pregnant dogs.

A large breeding kennel of Bulldogs (n = 57) experienced several Canid herpesvirus 1 (CHV-1)-related diseases in older puppies (9 weeks of age) in Arkansas. CHV-1 has been repeatedly confirmed in the kennel in several animals for 3 years (January 2012-February 2015) using various virology tests. I was able to detect a partial sequence of CHV DNA (~120 bp) in archived formalin-fixed, paraffin-embedded tissue blocks after 3 years of storage. CHV-1 is persistently circulating in this kennel in spite of high serum antibody titers in the adult dogs. The dogs were negative for canine brucellosis antibodies based on Brucella canis rapid card test.

Outbreaks of canid herpesvirus 1 disease in puppies in southern Brazil / Surtos de doença por herpesvírus canino 1 em filhotes de cães no sul do Brasil

Canid herpesvirus 1 (CHV-1) is a widespread pathogen of dogs and produces infertility, abortions and severe systemic disease in young puppies. Clinical data indicate the circulation of CHV-1 among Brazilian dogs yet definitive diagnosis has rarely been accomplished. This article describes the clinicopathological findings of four independent cases/outbreaks of neonatal disease by CHV-1 in Bulldog puppies followed by virus identification and genetic characterization. Three events occurred in a kennel holding dogs of different breeds at reproductive age (March 2013, October 2013 and April 2014). Puppies from three French or English Bulldog litters, aging 9 to 30 days were affected, presenting dyspnea, agonic breathing, pale mucous, abdominal pain and tension, evolving to death within about 24 hours. At necropsy, the puppies presented necrohemorrhagic hepatitis, multifocal and moderate necrohemorrhagic nephritis and fibrinonecrotic interstitial pneumonia. Virus isolation was positive in clinical specimens from one litter and CHV-1 DNA was detected by PCR in tissues from all four cases. Virus-neutralizing assays with samples of the affected kennel revealed 9/12 adult animals with high antibody titers to CHV-1. Nucleotide sequencing of glycoprotein B, C and D genes revealed 99-100% of identity among the viruses and with CHV-1 sequences available in GenBank. Phylogenetic analyses of gC sequences showed a segregation of the samples, even among three isolates from the same kennel. These findings support CHV-1 infection as the cause of disease and death in these dog litters, reinforcing the need for correct etiologic diagnosis, prevention and immunization against CHV-1 in dogs from Southern Brazil.

O herpesvírus canino (CHV-1) é um patógeno de cães que possui distribuição mundial e que causa infertilidade, abortos e doença sistêmica severa em filhotes de cães. Achados clínicos tem indicado a circulação do CHV-1 em cães no Brasil, embora o diagnóstico definitivo seja raramente determinado. Este artigo descreve os achados clinicopatológicos de quatro casos/surtos independentes de morte neonatal de filhotes de cães da raça Bulldog causados pelo CHV-1, a identificação e a caracterização genética do vírus. Três eventos ocorreram no mesmo canil que abriga animais de diferentes raças em idade reprodutiva (março de 2013, outubro de 2013 e abril de 2014). Filhotes de três ninhadas de Bulldog Francês e/ou Inglês, com idade de 9 a 30 dias, foram afetados e apresentaram dispneia, respiração agônica, mucosas pálidas, dor e tensão abdominal, que evoluíram para morte dos cães dentro de, aproximadamente, 24 horas. Na necropsia foram observados hepatite necro-hemorrágica, nefrite necro-hemorrágica multifocal e moderada e pneumonia intersticial fibrinonecrótica. O isolamento viral foi positivo em amostras clínicas de um filhote e DNA de CHV-1 foi detectado por PCR em tecidos de filhotes de todos os surtos. Teste de soroneutralização com amostras de soro de cães provenientes do canil afetado revelaram que nove de 12 animais adultos possuíam altos títulos de anticorpos para o CHV-1. Sequenciamento de nucleotídeos do gene das glicoproteínas B, C e D revelaram 99-100% de identidade entre as amostras e com as sequências de CHV-1 disponíveis no GenBank. A análise filogenética baseada na sequência do gene da glicoproteína C mostrou uma segregação das amostras, mesmo entre os três isolados de vírus provenientes do mesmo canil. Esses achados demonstram que o CHV-1 é a causa da doença e da morte dos filhotes, reforçando a necessidade do correto diagnóstico etiológico e a implementação de medidas de prevenção e imunização contra o CHV-1 em cães no sul do Brasil.