RESUMO
Bungowannah virus, which belongs to the genus Pestivirus within the family Flaviviridae, has been associated with myocarditis and a high incidence of stillbirths in pigs. In 2003, the virus was initially detected in a large pig farming complex on two separate sites in New South Wales, Australia. Until now, it has not been detected at other locations. Despite a program of depopulation and disinfection, the virus could be only eradicated from one of the affected farm complexes, the Bungowannah unit, but became endemic on the second complex, the Corowa unit. In the present study, the genetic variability of virus isolates collected between 2003 and 2014 in the endemically infected population has been retrospectively investigated. Phylogenetic analysis carried out based on sequences of the E2 and NS5B coding regions and the full-length open-reading frame revealed that the isolates from the different farm sites are closely related, but that samples collected between 2010 and 2014 at the Corowa farm site clustered in a different branch of the phylogenetic tree. Since 2010, a high-genetic stability of this RNA virus within the Corowa farm complex, probably due to an effective adaptation of the virus to the affected pig population, could be observed.
Assuntos
Infecções por Pestivirus/genética , Pestivirus/genética , Natimorto/genética , Doenças dos Suínos/genética , Animais , Austrália , Surtos de Doenças , Pestivirus/patogenicidade , Infecções por Pestivirus/veterinária , Infecções por Pestivirus/virologia , Estudos Retrospectivos , Natimorto/veterinária , Suínos , Doenças dos Suínos/virologiaRESUMO
Hendra virus occasionally causes severe disease in horses and humans. In Australia in 2013, infection was detected in a dog that had been in contact with an infected horse. Abnormalities and viral RNA were found in the dog's kidney, brain, lymph nodes, spleen, and liver. Dogs should be kept away from infected horses.
Assuntos
Cães/virologia , Vírus Hendra/patogenicidade , Infecções por Henipavirus/transmissão , Zoonoses/transmissão , Animais , Quirópteros/virologia , Cães/sangue , Infecções por Henipavirus/virologia , Doenças dos Cavalos/virologia , Cavalos/virologia , Queensland , Carga Viral/veterinária , Zoonoses/virologiaRESUMO
Orthobunyaviruses (order Bunyavirales, family Peribunyaviridae) in the Simbu serogroup have been responsible for widespread epidemics of congenital disease in ruminants. Australia has a national program to monitor arboviruses of veterinary importance. While monitoring for Akabane virus, a novel orthobunyavirus was detected. To inform the priority that should be given to this detection, a scoping review was undertaken to (1) characterise the associated disease presentations and establish which of the Simbu group viruses are of veterinary importance; (2) examine the diagnostic assays that have undergone development and validation for this group of viruses; and (3) describe the methods used to monitor the distribution of these viruses. Two search strategies identified 224 peer-reviewed publications for 33 viruses in the serogroup. Viruses in this group may cause severe animal health impacts, but only those phylogenetically arranged in clade B are associated with animal disease. Six viruses (Akabane, Schmallenberg, Aino, Shuni, Peaton, and Shamonda) were associated with congenital malformations, neurological signs, and reproductive disease. Diagnostic test interpretation is complicated by cross-reactivity, the timing of foetal immunocompetence, and sample type. Serological testing in surveys remains a mainstay of the methods used to monitor the distribution of SGVs. Given significant differences in survey designs, only broad mean seroprevalence estimates could be provided. Further research is required to determine the disease risk posed by novel orthobunyaviruses and how they could challenge current diagnostic and surveillance capabilities.
Assuntos
Infecções por Bunyaviridae , Doenças dos Bovinos , Orthobunyavirus , Vírus Simbu , Bovinos , Animais , Gado , Infecções por Bunyaviridae/diagnóstico , Infecções por Bunyaviridae/epidemiologia , Infecções por Bunyaviridae/veterinária , Estudos Soroepidemiológicos , Sorogrupo , Doenças dos Bovinos/diagnóstico , Doenças dos Bovinos/epidemiologia , Testes Diagnósticos de RotinaRESUMO
In the last decade, real-time polymerase chain reaction (PCR) has been increasingly adopted for bluetongue diagnosis with both broadly reactive and serotype-specific assays widely used. The use of these assays and nucleic acid sequencing technologies have enhanced bluetongue virus detection, resulting in the identification of a number of new serotypes. As a result, 27 different serotypes are officially recognised, and at least three more are proposed. Rapid identification of the virus serotype is essential for matching of antigens used in vaccines and to undertake surveillance and epidemiological studies to assist risk management. However, it is not uncommon for multiple serotypes to circulate in a region either concurrently or in successive years. It is therefore necessary to have a large suite of assays available to ensure that the full spectrum of viruses is detected. Nevertheless, covering a large range of virus serotypes is demanding from both a time and resource perspective. To overcome these challenges, real-time PCR assays were optimised to match local virus strains and then combined in a panel of quadriplex assays, resulting in three assays to detect 12 serotypes directly from blood samples from cattle and sheep. These multiplex assays have been used extensively for bluetongue surveillance in both sentinel animals and opportunistically collected samples. A protocol to adapt these assays to capture variations in local strains of bluetongue virus and to expand the panel is described. Collectively, these assays provide powerful tools for surveillance and the rapid identification of bluetongue virus serotypes directly from animal blood samples.
Assuntos
Vírus Bluetongue , Bluetongue , Doenças dos Bovinos , Ácidos Nucleicos , Doenças dos Ovinos , Animais , Bluetongue/diagnóstico , Bluetongue/epidemiologia , Vírus Bluetongue/genética , Bovinos , Doenças dos Bovinos/diagnóstico , Doenças dos Bovinos/epidemiologia , Reação em Cadeia da Polimerase em Tempo Real/métodos , Reação em Cadeia da Polimerase em Tempo Real/veterinária , Reação em Cadeia da Polimerase Via Transcriptase Reversa/veterinária , Sorogrupo , OvinosRESUMO
During the 2007 equine influenza outbreak in Australia, respiratory disease in dogs in close contact with infected horses was noted; influenza (H3N8) virus infection was confirmed. Nucleotide sequence of the virus from dogs was identical to that from horses. No evidence of dog-to-dog transmission or virus persistence in dogs was found.
Assuntos
Doenças do Cão/virologia , Doenças dos Cavalos/virologia , Vírus da Influenza A Subtipo H3N8 , Infecções por Orthomyxoviridae/veterinária , Sequência de Aminoácidos , Animais , Austrália/epidemiologia , Cães/virologia , Doenças dos Cavalos/transmissão , Cavalos/virologia , Vírus da Influenza A Subtipo H3N8/genética , Vírus da Influenza A Subtipo H3N8/patogenicidade , Dados de Sequência Molecular , Infecções por Orthomyxoviridae/epidemiologia , Infecções por Orthomyxoviridae/transmissão , Infecções por Orthomyxoviridae/virologia , FilogeniaRESUMO
Bungowannah virus is a novel porcine pestivirus identified in a disease outbreak in Australia in 2003. The aim of this study was to determine the outcome of infection of the pregnant pig with this virus. Twenty-four pregnant pigs were infected at days 35, 55, 75 or 90 of gestation. Blood, tonsillar and rectal swabs were collected from each pig at birth and then weekly until euthanasia or death. Tissues were sampled at necropsy. Viral load was measured by real-time reverse-transcription polymerase chain reaction (qRT-PCR) and antibody levels in serum by peroxidase-linked immunoassay. Bungowannah virus was detected in the serum and excretions of all infected pigs at birth regardless of the stage of gestation at which infection occurred. Persistent infections occurred following infection prior to the development of foetal immunocompetence. Unexpectedly some animals infected at day 55 of gestation later cleared the virus and seroconverted. Viraemia and viral shedding resolved quickest following infection in late gestation.
Assuntos
Idade Gestacional , Infecções por Pestivirus/patologia , Infecções por Pestivirus/veterinária , Pestivirus/isolamento & purificação , Complicações Infecciosas na Gravidez/virologia , Animais , Austrália , Feminino , Gravidez , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Suínos , Doenças dos Suínos/virologia , Carga Viral , Viremia/diagnósticoRESUMO
Bungowannah virus is a novel pestivirus identified from a disease outbreak in a piggery in Australia in June 2003. The aim of this study was to determine whether infection of pregnant pigs with Bungowannah virus induces the clinical signs and gross pathology observed during the initial outbreak and how this correlates with the time of infection. Twenty-four pregnant pigs were infected at one of four stages of gestation (approximately 35, 55, 75 or 90 days). The number of progeny born alive, stillborn or mummified, and signs of disease were recorded. Some surviving piglets were euthanased at weaning and others at ages up to 11 months. All piglets were subjected to a detailed necropsy. The greatest effects were observed following infection at 35 or 90 days of gestation. Infection at 35 days resulted in a significant reduction in the number of pigs born alive and an increased number of mummified foetuses (18%) and preweaning mortalities (70%). Preweaning losses were higher following infection at 90 days of gestation (29%) and were associated with sudden death and cardiorespiratory signs. Stunting occurred in chronically and persistently infected animals. This study reproduced the clinical signs and gross pathology of the porcine myocarditis syndrome and characterised the association between the time of infection and the clinical outcome.
Assuntos
Feto/virologia , Miocardite/veterinária , Infecções por Pestivirus/patologia , Infecções por Pestivirus/veterinária , Pestivirus/patogenicidade , Complicações Infecciosas na Gravidez/veterinária , Animais , Austrália , Feminino , Miocardite/patologia , Miocardite/virologia , Gravidez , Complicações Infecciosas na Gravidez/virologia , Suínos , Doenças dos Suínos/patologia , Doenças dos Suínos/virologiaRESUMO
Bungowannah virus is a pestivirus known to cause reproductive losses in pigs. The virus has not been found in other species, nor is it known if it has the capacity to cause disease in other animals. Eight sheep, eight calves and seven pregnant cows were experimentally infected with Bungowannah virus. It was found that sheep and calves could be infected. Furthermore, it was shown that the virus is able to cross the bovine placenta and cause infection of the foetus. These findings demonstrate the potential for species other than pigs to become infected with Bungowannah virus and the need to prevent them from becoming infected.
Assuntos
Feto/virologia , Troca Materno-Fetal/fisiologia , Infecções por Pestivirus/transmissão , Infecções por Pestivirus/veterinária , Pestivirus/patogenicidade , Animais , Bovinos , Doenças dos Bovinos/virologia , Feminino , Placenta/metabolismo , Placenta/virologia , Gravidez , Ovinos , Doenças dos Ovinos/virologia , Especificidade da Espécie , Suínos , Doenças dos Suínos/virologiaRESUMO
Infection of bulls with bovine viral diarrhoea virus (BVDV) can result in the development of virus persistence, confined to the reproductive tract. These bulls develop a normal immune response with high neutralizing antibody titres. However, BVDV can be excreted in the semen for a prolonged period. Although relatively rare, in this study we describe six separate cases in bulls being prepared for admission to artificial breeding centres. Semen samples were tested in a pan-Pestivirus-reactive real-time PCR assay and viral RNA was detected in semen from five of the bulls for three to eight months after infection. In one bull, virus was detected at low levels for more than five years. This bull was found to have one small testis. When slaughtered, virus was only detected in the abnormal testis. The low levels of BVDV in the semen of these bulls were only intermittently detected by virus isolation in cell culture. This virus-contaminated semen presents a biosecurity risk and confirms the need to screen all batches of semen from bulls that have been previously infected with BVDV. The use of real-time PCR is recommended as the preferred laboratory assay for this purpose.
Assuntos
Doença das Mucosas por Vírus da Diarreia Viral Bovina/epidemiologia , Doença das Mucosas por Vírus da Diarreia Viral Bovina/transmissão , Vírus da Diarreia Viral Bovina/isolamento & purificação , Sêmen/virologia , Animais , Anticorpos Neutralizantes/sangue , Anticorpos Antivirais/sangue , Doença das Mucosas por Vírus da Diarreia Viral Bovina/diagnóstico , Bovinos , Masculino , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Testículo/virologia , Viremia/virologiaRESUMO
In 2003 an outbreak of sudden deaths occurred in 2-3-week-old piglets on a piggery in New South Wales, Australia. There was a marked increase in the birth of stillborn piglets and preweaning losses associated with a multifocal non-suppurative myocarditis with myonecrosis. The aim of this study was to review existing data and to undertake further investigations of specimens from naturally infected pigs to provide evidence to support the hypothesis that Bungowannah virus, a recently recognised pestivirus, causes the porcine myocarditis syndrome (PMC). Sera collected from gilts and sows from affected and unaffected units were tested for Bungowannah virus antibody by a peroxidase-linked assay and Bungowannah virus RNA by qRT-PCR in selected cases. Stillborn piglets from affected and an unaffected unit were also tested for Bungowannah virus antibody and RNA. Body fluid IgG levels and the incidence of myocardial lesions in these stillborn piglets are summarised. Tissue sections from stillborn piglets with myocarditis/myonecrosis were examined for Bungowannah virus RNA by in situ hybridisation. A clear temporal association between the occurrence of PMC on a unit or module and exposure to Bungowannah virus was identified by serological tests in both breeding aged animals and stillborn pigs. In addition, at the individual animal level on affected units, Bungowannah virus RNA was detected in stillborn piglets in large amounts by qRT-PCR and in association with myocardial lesions by in situ hybridisation. The examination of field material from cases of PMC by serology, qRT-PCR and in situ hybridisation provides strong indirect evidence that Bungowannah virus is the causative agent for PMC.
Assuntos
Surtos de Doenças/veterinária , Miocardite/veterinária , Infecções por Pestivirus/veterinária , Pestivirus/isolamento & purificação , Doenças dos Suínos/virologia , Animais , Animais Recém-Nascidos , Feminino , Coração/virologia , Técnicas Imunoenzimáticas/veterinária , Imunoglobulina G/sangue , Hibridização In Situ/veterinária , Pulmão/virologia , Miocardite/epidemiologia , Miocardite/imunologia , Miocardite/virologia , New South Wales/epidemiologia , Pestivirus/genética , Pestivirus/imunologia , Infecções por Pestivirus/epidemiologia , Infecções por Pestivirus/imunologia , Infecções por Pestivirus/virologia , RNA Viral/química , RNA Viral/genética , Estudos Retrospectivos , Reação em Cadeia da Polimerase Via Transcriptase Reversa/veterinária , Suínos , Doenças dos Suínos/epidemiologia , Doenças dos Suínos/imunologiaRESUMO
In mid-February 2015, a large number of deaths were observed in the sole extant population of an endangered species of freshwater snapping turtle, Myuchelys georgesi, in a coastal river in New South Wales, Australia. Mortalities continued for approximately 7 weeks and affected mostly adult animals. More than 400 dead or dying animals were observed and population surveys conducted after the outbreak had ceased indicated that only a very small proportion of the population had survived, severely threatening the viability of the wild population. At necropsy, animals were in poor body condition, had bilateral swollen eyelids and some animals had tan foci on the skin of the ventral thighs. Histological examination revealed peri-orbital, splenic and nephric inflammation and necrosis. A virus was isolated in cell culture from a range of tissues. Nucleic acid sequencing of the virus isolate has identified the entire genome and indicates that this is a novel nidovirus that has a low level of nucleotide similarity to recognised nidoviruses. Its closest relatives are nidoviruses that have recently been described in pythons and lizards, usually in association with respiratory disease. In contrast, in the affected turtles, the most significant pathological changes were in the kidneys. Real time PCR assays developed to detect this virus demonstrated very high virus loads in affected tissues. In situ hybridisation studies confirmed the presence of viral nucleic acid in tissues in association with pathological changes. Collectively these data suggest that this virus is the likely cause of the mortalities that now threaten the survival of this species. Bellinger River Virus is the name proposed for this new virus.
Assuntos
Espécies em Perigo de Extinção , Nidovirales/genética , Nidovirales/isolamento & purificação , Tartarugas/virologia , Animais , Austrália , Lagartos , Nidovirales/patogenicidade , Filogenia , RNA Viral , RiosRESUMO
Bungowannah virus is a pestivirus identified from an outbreak of stillbirth and increased mortality in the first 3-4 weeks of life on a piggery in New South Wales, Australia in June 2003. The aims of this study were to determine if post-natal infection results in any clinical abnormalities and quantify the amount of Bungowannah virus RNA in blood, oropharyngeal, nasal and conjunctival excretions and faeces during the course of infection. Thirty pigs were infected intra-nasally with one of six different doses of Bungowannah virus or a control inoculum and clinical signs and rectal temperatures monitored. Sera, leukocytes and oropharyngeal, nasal, conjunctival, rectal and tissue swabs were tested for Bungowannah virus by qRT-PCR and sera for antibody by peroxidase linked assay and virus neutralisation test. The infectious dose by the intra-nasal route in weaner pigs was determined to be between 1.6 and 3.2 log(10) TCID(50). Few clinical signs could be attributed to infection. Viraemia and viral excretion in oropharyngeal secretions were detected from 3 days post-inoculation and seroconversion from 10 days post-inoculation. Viral shedding was greatest and most frequently detected in oropharyngeal, and to a lesser extent, nasal secretions, and generally detected in lower amounts and less frequently in conjunctival secretions and faeces.
Assuntos
Pestivirus/genética , Doenças dos Suínos/virologia , Animais , Surtos de Doenças/veterinária , Fezes/virologia , Testes de Neutralização , New South Wales/epidemiologia , Pestivirus/isolamento & purificação , RNA Viral/sangue , Sus scrofa , Suínos , Doenças dos Suínos/sangue , Doenças dos Suínos/epidemiologia , Doenças dos Suínos/imunologia , Viremia/epidemiologia , Viremia/veterinária , Viremia/virologia , Eliminação de Partículas Virais , DesmameRESUMO
In 2003 an outbreak of sudden deaths occurred in 2-3-week-old pigs on a piggery in New South Wales, Australia. There was a marked increase in the birth of stillborn pigs and preweaning losses associated with a multifocal non-suppurative myocarditis with myonecrosis. The aim of this study was to amplify any infectious agents present in field material to aid the detection and identification of the causative agent of the porcine myocarditis syndrome (PMC). Foetuses were directly inoculated in utero with tissue extracts from field cases of PMC at 56-60, 70-84 or 85-94 days of gestation and euthanased 7-28 days later. The IgG concentration in foetal sera/body fluids was measured, hearts were examined by light microscopy and selected hearts were examined by electron microscopy. An infectious agent was detected in tissues from cases of PMC and its identification as the novel pestivirus Bungowannah virus has recently been reported (Kirkland et al., 2007). Sow sera, foetal tissues and foetal sera/body fluids were tested for Bungowannah virus RNA by qRT-PCR and antibody by peroxidase-linked assay. Bungowannah virus was detected in numerous organs of the porcine foetus. Following direct foetal exposure it is probable that this virus spreads by direct intra-uterine transmission to adjacent foetuses and by trans-uterine transmission to the dam. Data were obtained for both the replication of the virus in the porcine foetus and the humoral immune response in the foetus and sow.