RESUMO
Since the first published report of bluetongue (BT) virus (BTV) infection in South America from Brazil in 1978, serological surveys have determined that the infection is widespread in sheep, cattle, goats and water buffalo but generally without clinical signs. Only four outbreaks of BT disease have been reported so far in Brazil. Brazil and Argentina are the only countries in South America where BTV serotypes 12 and 4 have been isolated, respectively. By serology, serotypes 4, 6, 14, 17, 19 and 20 were detected in Brazil, 12, 14 and 17 in Colombia, 14 and 17 in Guyana and 6, 14 and 17 in Suriname. Culicoides insignis is the predominant vector in the area, but C. pusillus could also be a BTV vector. The virus has not yet been isolated from the vector in the region.
RESUMO
Sentinel herds were monitored for the detection of bluetongue (BT)-specific antibodies and virus over two periods, namely: June 1999 to August 2000 and September 2000 to April 2001. Herds were located in Santo Tomé (Herds 1 and 2) where BTV activity was known to occur. From June 1999 to August 2000, the cumulative incidence (CI) of bluetongue virus (BTV) infection was 0% and 35% in Herds 1 and 2, respectively. In the second period, the CI of BTV infection was 10% and 97% in Herds 1 and 2, respectively. The virus was isolated from red blood cells of animals that seroconverted and was identified as serotype 4. Averages of the monthly maximal temperatures were always above 19 degrees C. However, averages of the monthly median temperatures were below 19 degrees C and averages of the monthly minimal temperatures were below 15 degrees C from May 2000 to August 2000. There was no viral activity detected at that time. Culicoides insignis was identified as the predominant potential vector species (99%) trapped near sentinel herds. Although clinical disease has never been reported in Argentina, viral activity was detected and the virus has been isolated in sentinel herds.
RESUMO
Serological diagnosis is very important for the detection of bovine viral diarrhea virus, an important pathogen related to reproductive failure. Methods normally used for the detection of antibodies are serum neutralization (SN) and ELISA. The objective of this work was to standardize an indirect ELISA with SN. With a diagnostic sensitivity of 98.31% and a diagnostic specificity of 100%, this ELISA-BVDV shows good sensitivity, specificity and repeatability. It is easy to transfer, economical, and easy to perform.
Assuntos
Anticorpos Antivirais/sangue , Doença das Mucosas por Vírus da Diarreia Viral Bovina/sangue , Vírus da Diarreia Viral Bovina/imunologia , Ensaio de Imunoadsorção Enzimática/métodos , Animais , Doença das Mucosas por Vírus da Diarreia Viral Bovina/diagnóstico , Doença das Mucosas por Vírus da Diarreia Viral Bovina/imunologia , Bovinos , Linhagem Celular/virologia , Ensaio de Imunoadsorção Enzimática/normas , Testes de Neutralização , Padrões de Referência , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Estudos SoroepidemiológicosRESUMO
El diagnóstico serológico es de gran importancia para la detección de la infección con el virus de la diarrea viral bovina (BVDV), importante patógeno asociado a fallas reproductivas entre otras. Las técnicas más utilizadas para la detección de anticuerpos contra BVDV son la seroneutralización en cultivos celulares (SN) y el ELISA. El objetivo del presente trabajo fue estandarizar un ELISA de esquema indirecto comparando sus resultados con la SN. Con resultados de sensibilidad de diagnóstico mayores o iguales que 98,31 por ciento y de especificidad de diagnóstico igual a 100 por ciento, el ELISA-BVDV resultó ser un método sensible, específico y repetible. Además es una técnica de realización rápida, sencilla, económica y de fácil transferencia.
Assuntos
Animais , Argentina , Vírus da Diarreia Viral Bovina , Ensaio de Imunoadsorção Enzimática , Testes de Neutralização , Testes SorológicosRESUMO
El diagnóstico serológico es de gran importancia para la detección de la infección con el virus de la diarrea viral bovina (BVDV), importante patógeno asociado a fallas reproductivas entre otras. Las técnicas más utilizadas para la detección de anticuerpos contra BVDV son la seroneutralización en cultivos celulares (SN) y el ELISA. El objetivo del presente trabajo fue estandarizar un ELISA de esquema indirecto comparando sus resultados con la SN. Con resultados de sensibilidad de diagnóstico mayores o iguales que 98,31 por ciento y de especificidad de diagnóstico igual a 100 por ciento, el ELISA-BVDV resultó ser un método sensible, específico y repetible. Además es una técnica de realización rápida, sencilla, económica y de fácil transferencia. (AU)
Assuntos
Animais , Vírus da Diarreia Viral Bovina , Testes Sorológicos , Ensaio de Imunoadsorção Enzimática , Testes de Neutralização , ArgentinaRESUMO
Serological diagnosis is very important for the detection of bovine viral diarrhea virus, an important pathogen related to reproductive failure. Methods normally used for the detection of antibodies are serum neutralization (SN) and ELISA. The objective of this work was to standardize an indirect ELISA with SN. With a diagnostic sensitivity of 98.31
and a diagnostic specificity of 100
, this ELISA-BVDV shows good sensitivity, specificity and repeatability. It is easy to transfer, economical, and easy to perform.
RESUMO
To establish if BTV was circulating in Argentina, 94 bovines from the Santo Tomé and Ituzaingó Departments of Corrientes Province were sampled every 30-60 days during 14 months. Red blood cells from those animals that showed seroconvertion with a c-ELISA were processed for virus isolation by inoculation in embryonated chicken eggs and cell cultures. Cells with CPE were positive by direct and indirect immunofluorescence with BTV specific reagents. These samples examined by electron microscopy showed virus particles with BTV morphological characteristics. Blood samples and tissue culture supernantants were positive by RT-PCR technique with primers corresponding to the segment 3 of the BTV genome. Haematophagous insects were captured in one farm using light traps and Culicoides insignis Lutz was the predominant species detected. This is the first isolation of BTV in Argentina from northeastern bovines without any disease symptom.
Assuntos
Vírus Bluetongue/isolamento & purificação , Bluetongue/virologia , Doenças dos Bovinos/virologia , Ceratopogonidae/virologia , Insetos Vetores/virologia , Animais , Anticorpos Antivirais/sangue , Argentina/epidemiologia , Bluetongue/epidemiologia , Bluetongue/transmissão , Vírus Bluetongue/genética , Vírus Bluetongue/imunologia , Bovinos , Doenças dos Bovinos/epidemiologia , Doenças dos Bovinos/transmissão , Células Cultivadas/virologia , Galinhas , Ovos , Ensaio de Imunoadsorção Enzimática , Genoma Viral , RNA Viral/genética , Estações do Ano , Cultura de VírusRESUMO
To establish if BTV was circulating in Argentina, 94 bovines from the Santo TomÚ and Ituzaingó Departments of Corrientes Province were sampled every 30-60 days during 14 months. Red blood cells from those animals that showed seroconvertion with a c-ELISA were processed for virus isolation by inoculation in embryonated chicken eggs and cell cultures. Cells with CPE were positive by direct and indirect immunofluorescence with BTV specific reagents. These samples examined by electron microscopy showed virus particles with BTV morphological characteristics. Blood samples and tissue culture supernantants were positive by RT-PCR technique with primers corresponding to the segment 3 of the BTV genome. Haematophagous insects were captured in one farm using light traps and Culicoides insignis Lutz was the predominant species detected. This is the first isolation of BTV in Argentina from northeastern bovines without any disease symptom.
Assuntos
Animais , Bovinos , Bluetongue , Ceratopogonidae , Doenças dos Bovinos/virologia , Insetos Vetores , Vírus Bluetongue/isolamento & purificação , Anticorpos Antivirais , Argentina , Bluetongue , Células Cultivadas/virologia , Galinhas , Doenças dos Bovinos/epidemiologia , Doenças dos Bovinos/transmissão , Ovos , Ensaio de Imunoadsorção Enzimática , Genoma Viral , RNA Viral , Estações do Ano , Vírus Bluetongue/genética , Vírus Bluetongue/imunologia , Cultura de VírusRESUMO
To establish if BTV was circulating in Argentina, 94 bovines from the Santo TomU and Ituzaingó Departments of Corrientes Province were sampled every 30-60 days during 14 months. Red blood cells from those animals that showed seroconvertion with a c-ELISA were processed for virus isolation by inoculation in embryonated chicken eggs and cell cultures. Cells with CPE were positive by direct and indirect immunofluorescence with BTV specific reagents. These samples examined by electron microscopy showed virus particles with BTV morphological characteristics. Blood samples and tissue culture supernantants were positive by RT-PCR technique with primers corresponding to the segment 3 of the BTV genome. Haematophagous insects were captured in one farm using light traps and Culicoides insignis Lutz was the predominant species detected. This is the first isolation of BTV in Argentina from northeastern bovines without any disease symptom.(AU)
Assuntos
Animais , Bovinos , Bluetongue/virologia , Vírus Bluetongue/isolamento & purificação , Doenças dos Bovinos/virologia , Ceratopogonidae/virologia , Insetos Vetores/virologia , Anticorpos Antivirais/sangue , Argentina/epidemiologia , Bluetongue/epidemiologia , Bluetongue/transmissão , Vírus Bluetongue/genética , Vírus Bluetongue/imunologia , Doenças dos Bovinos/epidemiologia , Doenças dos Bovinos/transmissão , Células Cultivadas/virologia , Galinhas , Ovos , Ensaio de Imunoadsorção Enzimática , Genoma Viral , RNA Viral/genética , Estações do Ano , Cultura de VírusRESUMO
To establish if BTV was circulating in Argentina, 94 bovines from the Santo Tomé and Ituzaingó Departments of Corrientes Province were sampled every 30-60 days during 14 months. Red blood cells from those animals that showed seroconvertion with a c-ELISA were processed for virus isolation by inoculation in embryonated chicken eggs and cell cultures. Cells with CPE were positive by direct and indirect immunofluorescence with BTV specific reagents. These samples examined by electron microscopy showed virus particles with BTV morphological characteristics. Blood samples and tissue culture supernantants were positive by RT-PCR technique with primers corresponding to the segment 3 of the BTV genome. Haematophagous insects were captured in one farm using light traps and Culicoides insignis Lutz was the predominant species detected. This is the first isolation of BTV in Argentina from northeastern bovines without any disease symptom.
RESUMO
Bluetongue (BT) is a viral disease of domestic and wild ruminants. It is particularly damaging in sheep, where up to half of infected animals may die, showing inflammation and hemorrhages of the mucous membranes of the mouth, nose, and intestines. In cattle and goats, BT rarely causes disease, however it can affect the animal's reproductive ability, so that losses are not easily estimated. Bluetongue virus spreads from animal to animal by biting insects of the genus Culicoides; and this is the reason why the disease is more prevalent in geographic areas where climate conditions are favourable for their development. The disease was first recognized in South Africa in the late 1700's, but it was not until the early 1900's that it was described in detail, and at present, epizootiology and pathogenesis studies are still being carried on.
Assuntos
Vírus Bluetongue , Bluetongue , Aborto Animal/etiologia , Aborto Animal/virologia , Animais , Antígenos Virais/imunologia , Argentina/epidemiologia , Bluetongue/diagnóstico , Bluetongue/etiologia , Bluetongue/história , Bluetongue/prevenção & controle , Vírus Bluetongue/classificação , Vírus Bluetongue/isolamento & purificação , Vírus Bluetongue/fisiologia , Ceratopogonidae/virologia , Feminino , Doenças Fetais/veterinária , Doenças Fetais/virologia , História do Século XVII , História do Século XIX , História do Século XX , Infertilidade Masculina/veterinária , Infertilidade Masculina/virologia , Insetos Vetores , Masculino , RNA Viral/análise , Ruminantes , Proteínas Virais/imunologia , Vacinas ViraisRESUMO
Bluetongue (BT) is a viral disease of domestic and wild ruminants. It is particularly damaging in sheep, where up to half of infected animals may die, showing inflammation and hemorrhages of the mucous membranes of the mouth, nose, and intestines. In cattle and goats, BT rarely causes disease, however it can affect the animal's reproductive ability, so that losses are not easily estimated. Bluetongue virus spreads from animal to animal by biting insects of the genus Culicoides; and this is the reason why the disease is more prevalent in geographic areas where climate conditions are favourable for their development. The disease was first recognized in South Africa in the late 1700's, but it was not until the early 1900's that it was described in detail, and at present, epizootiology and pathogenesis studies are still being carried on.
Assuntos
Animais , Masculino , Feminino , Bluetongue , Vírus Bluetongue , Aborto Animal , Antígenos Virais/imunologia , Argentina , Bluetongue , Ceratopogonidae , Doenças Fetais/veterinária , Doenças Fetais/virologia , Infertilidade Masculina , Insetos Vetores , Proteínas Virais/imunologia , RNA Viral , Ruminantes , Vacinas Virais , Vírus Bluetongue/classificação , Vírus Bluetongue/isolamento & purificação , Vírus Bluetongue/fisiologiaRESUMO
Bluetongue (BT) is a viral disease of domestic and wild ruminants. It is particularly damaging in sheep, where up to half of infected animals may die, showing inflammation and hemorrhages of the mucous membranes of the mouth, nose, and intestines. In cattle and goats, BT rarely causes disease, however it can affect the animals reproductive ability, so that losses are not easily estimated. Bluetongue virus spreads from animal to animal by biting insects of the genus Culicoides; and this is the reason why the disease is more prevalent in geographic areas where climate conditions are favourable for their development. The disease was first recognized in South Africa in the late 1700s, but it was not until the early 1900s that it was described in detail, and at present, epizootiology and pathogenesis studies are still being carried on.(AU)
Assuntos
Animais , Masculino , Feminino , Bluetongue , Vírus Bluetongue , Aborto Animal/etiologia , Aborto Animal/virologia , Antígenos Virais/imunologia , Argentina/epidemiologia , Bluetongue/diagnóstico , Bluetongue/etiologia , Bluetongue/história , Bluetongue/prevenção & controle , Vírus Bluetongue/classificação , Vírus Bluetongue/isolamento & purificação , Vírus Bluetongue/fisiologia , Ceratopogonidae/virologia , Doenças Fetais/veterinária , Doenças Fetais/virologia , Infertilidade Masculina/veterinária , Infertilidade Masculina/virologia , Insetos Vetores , RNA Viral/análise , Ruminantes , Proteínas Virais/imunologia , Vacinas ViraisRESUMO
Bluetongue (BT) is a viral disease of domestic and wild ruminants. It is particularly damaging in sheep, where up to half of infected animals may die, showing inflammation and hemorrhages of the mucous membranes of the mouth, nose, and intestines. In cattle and goats, BT rarely causes disease, however it can affect the animals reproductive ability, so that losses are not easily estimated. Bluetongue virus spreads from animal to animal by biting insects of the genus Culicoides; and this is the reason why the disease is more prevalent in geographic areas where climate conditions are favourable for their development. The disease was first recognized in South Africa in the late 1700s, but it was not until the early 1900s that it was described in detail, and at present, epizootiology and pathogenesis studies are still being carried on.
RESUMO
Fetal bovine serum (FBS) used in cell culture may be contaminated with viruses, among them bovine viral diarrhea virus (BVDV) affecting the production of biological reagents and the results of diagnosis. The filtration process used in the preparation of commercial FBS abrogates most viral agents that may be present in raw FBS, but BVDV may pass through the filters because of its small size and its pleomorphism. While detection of bovine herpes virus-1 and parainfluenza-3 (PI-3) is determined by observation of the cytopathic effect, and also by hemadsorption in the case of PI-3, the most frequently isolated BVDV is non cytopathic, and infects cells without morphological alterations, inducing problems that arise after several cell generations. Batches of raw and processed FBS were analyzed. Frequencies of BVDV detection in raw serum in Argentina were similar to those published for USA. By conventional methods for BVDV detection, only 2 of 20 commercial batches of FBS had BVDV. Using cell cultures maintained with high concentrations of the serum under study for at least 2 weeks, with detection of viral antigen by indirect immunofluorescence, the percentage of BVDV detection was 80%. This method shows that most lots of commercial FBS contain BVDV. RT-PCR allows faster detection of the viral genome, but it must be validated, as it does not show viral replication. To eliminate the problem of BVDV contamination in FBS, only gamma irradiated FBS is used in our laboratory.
Assuntos
Sangue/virologia , Vírus da Diarreia Viral Bovina/isolamento & purificação , Animais , Bovinos , Meios de CulturaRESUMO
Fetal bovine serum (FBS) used in cell culture may be contaminated with viruses, among them bovine viral diarrhea virus (BVDV) affecting the production of biological reagents and the results of diagnosis. The filtration process used in the preparation of commercial FBS abrogates most viral agents that may be present in raw FBS, but BVDV may pass through the filters because of its small size and its pleomorphism. While detection of bovine herpes virus-1 and parainfluenza-3 (PI-3) is determined by observation of the cytopathic effect, and also by hemadsorption in the case of PI-3, the most frequently isolated BVDV is non cytopathic, and infects cells without morphological alterations, inducing problems that arise after several cell generations. Batches of raw and processed FBS were analyzed. Frequencies of BVDV detection in raw serum in Argentina were similar to those published for USA. By conventional methods for BVDV detection, only 2 of 20 commercial batches of FBS had BVDV. Using cell cultures maintained with high concentrations of the serum under study for at least 2 weeks, with detection of viral antigen by indirect immunofluorescence, the percentage of BVDV detection was 80. This method shows that most lots of commercial FBS contain BVDV. RT-PCR allows faster detection of the viral genome, but it must be validated, as it does not show viral replication. To eliminate the problem of BVDV contamination in FBS, only gamma irradiated FBS is used in our laboratory.
Assuntos
Animais , Bovinos , Sangue , Vírus da Diarreia Viral Bovina/isolamento & purificação , Meios de CulturaRESUMO
Fetal bovine serum (FBS) used in cell culture may be contaminated with viruses, among them bovine viral diarrhea virus (BVDV) affecting the production of biological reagents and the results of diagnosis. The filtration process used in the preparation of commercial FBS abrogates most viral agents that may be present in raw FBS, but BVDV may pass through the filters because of its small size and its pleomorphism. While detection of bovine herpes virus-1 and parainfluenza-3 (PI-3) is determined by observation of the cytopathic effect, and also by hemadsorption in the case of PI-3, the most frequently isolated BVDV is non cytopathic, and infects cells without morphological alterations, inducing problems that arise after several cell generations. Batches of raw and processed FBS were analyzed. Frequencies of BVDV detection in raw serum in Argentina were similar to those published for USA. By conventional methods for BVDV detection, only 2 of 20 commercial batches of FBS had BVDV. Using cell cultures maintained with high concentrations of the serum under study for at least 2 weeks, with detection of viral antigen by indirect immunofluorescence, the percentage of BVDV detection was 80. This method shows that most lots of commercial FBS contain BVDV. RT-PCR allows faster detection of the viral genome, but it must be validated, as it does not show viral replication. To eliminate the problem of BVDV contamination in FBS, only gamma irradiated FBS is used in our laboratory.(AU)
Assuntos
Animais , Bovinos , Sangue/virologia , Vírus da Diarreia Viral Bovina/isolamento & purificação , Meios de CulturaRESUMO
Fetal bovine serum (FBS) used in cell culture may be contaminated with viruses, among them bovine viral diarrhea virus (BVDV) affecting the production of biological reagents and the results of diagnosis. The filtration process used in the preparation of commercial FBS abrogates most viral agents that may be present in raw FBS, but BVDV may pass through the filters because of its small size and its pleomorphism. While detection of bovine herpes virus-1 and parainfluenza-3 (PI-3) is determined by observation of the cytopathic effect, and also by hemadsorption in the case of PI-3, the most frequently isolated BVDV is non cytopathic, and infects cells without morphological alterations, inducing problems that arise after several cell generations. Batches of raw and processed FBS were analyzed. Frequencies of BVDV detection in raw serum in Argentina were similar to those published for USA. By conventional methods for BVDV detection, only 2 of 20 commercial batches of FBS had BVDV. Using cell cultures maintained with high concentrations of the serum under study for at least 2 weeks, with detection of viral antigen by indirect immunofluorescence, the percentage of BVDV detection was 80
. This method shows that most lots of commercial FBS contain BVDV. RT-PCR allows faster detection of the viral genome, but it must be validated, as it does not show viral replication. To eliminate the problem of BVDV contamination in FBS, only gamma irradiated FBS is used in our laboratory.
RESUMO
The frequency of isolation of bovine viral diarrhoea virus (BVDV) from primary tissue cultures and organs from bovine foetuses was studied between 1992 and 1994. Around 25% of primary tissue cultures were BVDV positive. Primary testis cultures were inoculated with homogenates of spleen, kidney, lung and liver from 52 foetuses. Cells were passaged twice and BVDV antigen investigated by indirect immunofluorescence. Non-cytopathic BVDV was detected in at least one organ in 11/52 foetuses (21.2%): 6/10 spleens, 4/7 kidneys, 7/9 lungs and 3/5 livers. Cytopathic BVDV was detected in lung and kidney from two foetuses. Since only gamma-irradiated sera are used in the laboratory and only inactivated BVDV vaccines are applied in Argentina, it was concluded that these isolations represented field infections. In addition to the 11 virus positive foetuses, two foetuses were positive for BVDV antibodies, which suggested a 25% prevalence of infection. These results stress the need for disease control on a herd basis and the requirement for biological reagents of bovine origin for the detection of BVDV.
Assuntos
Doença das Mucosas por Vírus da Diarreia Viral Bovina/virologia , Vírus da Diarreia Viral Bovina/isolamento & purificação , Doenças Fetais/veterinária , Animais , Argentina/epidemiologia , Doença das Mucosas por Vírus da Diarreia Viral Bovina/epidemiologia , Bovinos , Feminino , Doenças Fetais/epidemiologia , Doenças Fetais/virologia , Masculino , PrevalênciaRESUMO
In order to establish the prevalence of viral infections of the bovine fetus in Argentina, a serological survey for antibodies against viral agents currently affecting cattle in this country was conducted. Antibodies against foot-and-mouth disease virus (FMDV), bovine herpesvirus-1 (BHV-1), bovine leukaemia virus (BLV), bovine rotavirus (BRV), bovine coronavirus (BCV), bovine viral diarrhoea virus (BVDV) and parainfluenza-3 (PI-3) were investigated in a total of 315 fetal serum samples. Conventional techniques were used: indirect immunofluorescence (FMDV, BHV-1, BVDV and BCV), radial immunodiffusion (BLV), ELISA (BRV) and haemagglutination inhibition (PI-3). Antibodies against BHV-1, BVDV and PI-3 were detected in samples from fetuses in the second and third trimester of gestation, with a prevalence of 1.21 per cent (two of 165), 2.03 per cent (four of 197) and 5.08 per cent (nine of 177), respectively. Either antibodies or non-antibody factors able to bind to BRV and BCV antigens were detected with a prevalence of 2.44 per cent (five of 205) and 4.54 per cent (five of 110), respectively. In addition, 14.68 per cent of non-specific inhibitors of PI-3 mediated haemagglutination were found. No seropositives against FMDV and BLV were detected.