Assuntos
Doenças dos Animais/prevenção & controle , Guias de Prática Clínica como Assunto , Vacinação/veterinária , Vacinas/normas , Animais , Diagnóstico Diferencial , Cooperação Internacional , Vacinação/legislação & jurisprudência , Vacinação/normas , Vacinas/administração & dosagem , Vacinas MarcadorasRESUMO
Bovine spongiform encephalopathy (BSE) is a neurodegenerative disease of cattle caused by prions that was first described in the United Kingdom (UK) in 1986. The BSE epizootic that commenced in the UK in the 1980s has since spread into other countries in Europe and Asia through exports of contaminated meat-and-bone meal or infected cattle. Over the past few years, other emerging or reemerging diseases have spread into previously free countries or regions through international trade. This negative effect of globalisation means that to implement successful preventive and strategic programmes to safeguard animal health, such programmes must, as a priority, take a regional approach. Global thinking, regional planning and local performance constitute the key factors for the successful control of animal diseases. In South America, initial preventive actions against BSE were adopted in 1989. Further measures adopted since then and based on new scientific and technical findings, have led to the demonstration that the region is free of BSE. These early preventive actions have reliably protected the region from importing BSE-infected material. An integral part of the project to determine the BSE status of South America was the training of personnel, the incorporation of technology and the provision of updated information through close relationships with international organisations and prominent international researcher workers. Regional activities aimed at harmonising BSE prevention programmes, producing objective and transparent data on the equivalence of regional BSE status and facilitating regional and international trade have recently been launched. Maintaining the BSE-free status of the region must be given high priority by the beef agro-industrial sectors.
Assuntos
Doenças Transmissíveis Emergentes/veterinária , Encefalopatia Espongiforme Bovina/prevenção & controle , Animais , Bovinos , Doenças Transmissíveis Emergentes/epidemiologia , Doenças Transmissíveis Emergentes/prevenção & controle , Encefalopatia Espongiforme Bovina/epidemiologia , Saúde Global , Humanos , Medição de Risco , Fatores de Risco , América do Sul/epidemiologiaRESUMO
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
This study analysed sera from 390 llamas (Lama glama) from nine farms located in three different Argentine provinces: Buenos Aires, Cordoba and Jujuy. The samples were tested for antibodies against 8 virus known to infect cattle: bovine herpesvirus type 1 (BHV-1), bovine viral diarrhea virus (BVDV), bovine adenovirus (BAdV III), bovine enterovirus (BEV), bovine rotavirus (BRV), bluetongue virus (BTV), bovine leukaemia virus (BLV), and foot-and-mouth virus (FMDV) by conventional methods such as seroneutralization, immunoperoxidase staining, and agar gel immunodiffusion. The antibody prevalences detected in llamas were: BHV-1 in 0.77% (3/390), BVDV in 2.05% (8/390), BAdV III in 5.13% (20/390), BEV in 4.10% (16/390), BRV in 87.69% (342/390). No antibodies against BTV, BLV and VIAA (FMDV infection associated antigen) were detected.
Assuntos
Anticorpos Antivirais/sangue , Camelídeos Americanos/imunologia , Viroses/veterinária , Animais , Argentina , Camelídeos Americanos/sangue , Bovinos , Doenças dos Bovinos/virologia , Linhagem Celular , Testes Sorológicos , Viroses/diagnóstico , Viroses/imunologia , Vírus/crescimento & desenvolvimento , Vírus/imunologia , Vírus/isolamento & purificaçãoRESUMO
The authors review the policies designed to prevent and deal with animal health emergencies which have been implemented in countries of South America. They describe the evolution of the epidemiological situation of the continent, the new arrangements for international trade in animals and products of animal origin arising from the creation of the World Trade Organization (WTO), and the consequences of such developments for livestock production in South America. Veterinary systems used to prevent and deal with emergencies in the eleven OIE Member Countries on the continent are described, together with emerging problems which confront the Veterinary Services of the continent, namely: exotic diseases, abnormal occurrence of endemic diseases subject to control programmes, faults in food-safety mechanisms, diseases which have an environmental impact, and problems connected with animal welfare. The emergencies which present the greatest risk to South America are foot and mouth diseases, transmissible spongiform encephalopathies, the porcine reproductive and respiratory syndrome, food poisoning, Newcastle disease and fowl plague. Other problems are the appearance of new strains of existing agents, and the presence of resistant individuals among species of bacteria or harmful arthropods. The authors emphasise the need to co-ordinate the prevention of emergencies with development work at the international level, particularly regional and international agreements, harmonization of procedures, progress in animal health and public health, risk analysis, etc. These systems and methods of prevention have a contribution to make in enhancing the potential of animal production in South America, and the adoption of stricter health and quality standards, according to criteria established by the WTO Agreement on the Application of Sanitary and Phytosanitary Measures.
Assuntos
Doenças dos Animais/prevenção & controle , Animais Domésticos , Surtos de Doenças/veterinária , Doenças dos Animais/epidemiologia , Animais , Surtos de Doenças/prevenção & controle , Emergências/veterinária , América do Sul/epidemiologiaRESUMO
The development of a liquid-phase blocking sandwich ELISA (LPBE) to measure antibodies (Ab) produced in cattle with the O, A and C foot-and-mouth disease virus (FMDV) types of commercial vaccines used in Argentina is described. The test was specific: 99% of naïve cattle sera (n = 130) gave titres below log10 = 1.2, and none had a titre above log10 = 1.5. Comparative studies with serum neutralization test (SNT) using sera from cattle which received one or more vaccine doses is reported. The overall rank correlation coefficient (Spearman's rho, rs) between SNT and LPBE were highly significant (rs > 0.67, P < 0.0001) for all vaccine strains. LBPE Ab titres on sera collected 90 days post vaccination were compared with results of cattle protection tests by applying a logistic regression. The minimum Ab titres at which 85% and 75% of the cattle were protected for each FMDV type were determined in order to interpret field Ab data in terms of protection. Application of this method allows large scale serological examinations to monitor antibody levels in vaccinated animals as an indirect indicator of the FMD control program status in the field. Its use in the evaluation of commercial batches of FMD vaccine is discussed.
Assuntos
Anticorpos Antivirais/sangue , Aphthovirus/imunologia , Doenças dos Bovinos/prevenção & controle , Febre Aftosa/prevenção & controle , Vacinas Virais/imunologia , Animais , Argentina/epidemiologia , Bovinos , Doenças dos Bovinos/epidemiologia , Doenças dos Bovinos/imunologia , Surtos de Doenças/veterinária , Ensaio de Imunoadsorção Enzimática/veterinária , Febre Aftosa/epidemiologia , Febre Aftosa/imunologia , Modelos Logísticos , Testes de Neutralização/veterinária , Coelhos , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Vacinação/veterináriaRESUMO
A sero-epidemiological survey was conducted in two districts in Argentina between 1993 and 1995, to provide additional information on the epidemiology of foot and mouth disease (FMD) in Argentina and to assess the level of immunity in cattle populations, and the circulation of FMD virus. As part of the final stage of this survey, a comparison was made of the results obtained by the enzyme-linked immunosorbent assay (ELISA) and agar gel immunodiffusion techniques. Levels of population immunity against the four types of virus included in the vaccine increased progressively during the period of the survey until, in 1995, at the end of the vaccination period, the percentage of animals possessing adequate levels of protection was approximately 77% in yearlings, and more than 94% in cattle over one year old. During the three-year study, there was a clear tendency for viral activity to diminish, until in 1995 when between 3% and 0.6% were positive to the agar gel immunodiffusion test for the antigen associated with viral infection. By contrast, the ELISA detected antibody in about five times as many animals. The authors show how the increase in the level of population immunity was accompanied by a fall in viral activity.
Assuntos
Anticorpos Antivirais/sangue , Aphthovirus/imunologia , Doenças dos Bovinos/epidemiologia , Febre Aftosa/epidemiologia , Animais , Argentina/epidemiologia , Bovinos , Doenças dos Bovinos/prevenção & controle , Ensaio de Imunoadsorção Enzimática/veterinária , Febre Aftosa/prevenção & controle , Imunodifusão/veterinária , Estudos SoroepidemiológicosRESUMO
The analysis of sera obtained from animals vaccinated or revaccinated with inactivated vaccines against foot and mouth disease (FMD) virus showed that these vaccines induced antibodies against the virus infection-associated (VIA) antigen, detectable by agar gel immunodiffusion (AGID). The present study evaluates the antibody response to protein 3D and the VIA antigen (VIAA) of FMD virus induced by different vaccines in a group of 51 calves. This response was detected using AGID and a liquid-phase blocking sandwich enzyme-linked immunosorbent assay (ELISA) for anti-3D antibodies (ELISA-3D). No anti-VIAA or anti-3D antibodies were detected after the initial vaccination. Following revaccination, animals giving positive results were detected by both methods. This immune response disappeared 60-120 days post-revaccination (dprv) according to the AGID method, and 90-180 dprv when ELISA-3D was used. Samples of oesophageal-pharyngeal fluid obtained from animals that remained positive for anti-VIAA antibodies at 90-120 dprv gave negative results for viral isolation, indicating that the transitional antibody response induced by the vaccine was due to the presence of non-structural antigens in the vaccine and not to viral infection. These results indicate that the ELISA-3D method could be used as a complementary method for sero-epidemiological studies as an indirect indicator of viral activity, as long as the age and vaccination status of the animals being sampled are taken into consideration.
Assuntos
Anticorpos Antivirais/sangue , Aphthovirus/imunologia , Doenças dos Bovinos/imunologia , Febre Aftosa/imunologia , Vacinas Virais/imunologia , Animais , Anticorpos Antivirais/análise , Antígenos Virais/imunologia , Bovinos , Doenças dos Bovinos/prevenção & controle , RNA Polimerases Dirigidas por DNA/imunologia , Ensaio de Imunoadsorção Enzimática/veterinária , Esôfago/imunologia , Febre Aftosa/prevenção & controle , Imunodifusão/veterinária , Faringe/imunologia , Ovinos , Vacinação/veterinária , Vacinas de Produtos Inativados/imunologiaRESUMO
A liquid-phase blocking sandwich enzyme-linked immunosorbent assay (ELISA-3D) was developed to detect specific antibodies to the 3D protein in sera from foot-and-mouth disease (FMD) virus (FMDV)-infected animals. The assay uses a nonstructural 3D recombinant protein and two polyclonal antisera, one for capture (bovine) and the other for detector (guinea pig). The specificity of the assay was demonstrated by negative results with 101 sera of cattle from the FMD-free zone in Argentina and with bovine and porcine sera raised against various RNA and DNA viruses. The ELISA-3D was able to detect antibodies in cattle after natural or experimental infection with FMDV of A, O, or C types as early as 5 days postinfection and at later stages in persistently infected animals. Comparison of the results with those obtained with the routinely used agar gel immunodiffusion test and a previously described ELISA, both employing a partially purified virus-infection-associated antigen, shows that the ELISA-3D is highly sensitive and specific and gives reproducible results. Its use as a tool for monitoring viral activity and for certification of FMDV-free animals is recommended.
Assuntos
Anticorpos Antivirais/sangue , Antígenos Virais/imunologia , Febre Aftosa/imunologia , Proteínas não Estruturais Virais/imunologia , Animais , Especificidade de Anticorpos , Aphthovirus/imunologia , Argentina , Bovinos , Ensaio de Imunoadsorção Enzimática/métodos , Febre Aftosa/sangue , Febre Aftosa/diagnóstico , Glutationa Transferase , Cobaias , Engenharia de Proteínas , Proteínas Recombinantes de Fusão/imunologia , Sensibilidade e Especificidade , Suínos , Fatores de Tempo , Vacinação , Vacinas ViraisRESUMO
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
An experimental trial was conducted to evaluate the ability of foot-and-mouth-disease (FMD) virus (serotypes A79, C3, O1) to infect susceptible llamas exposed either directly to affected livestock, or indirectly to llamas that had been directly exposed to affected livestock. In addition, susceptible livestock species (cattle, pigs, goats, and sheep) were exposed to those llamas that had been both directly and indirectly exposed to the FMD virus to further look at potential transmission possibilities. Of 30 llamas directly exposed to the FMD virus, only three (3/30) showed evidence of infection, and of those, only two (2/30) had mild clinical signs. No FMD virus was isolated from either oesophageal-pharyngeal (OP) fluid or blood samples collected from the infected llamas beyond 14 days post-exposure. There was no evidence of virus transmission between the directly exposed and indirectly exposed llamas or between both groups of llamas and susceptible domestic livestock, as determined by the lack of clinical signs, by virus isolation, and by serology results. These results provide further evidence that llamas are resistant to FMD infection, and that they play a minor role, if any, in transmitting the virus to domestic livestock.
Assuntos
Aphthovirus/fisiologia , Camelídeos Americanos , Febre Aftosa/epidemiologia , Animais , Aphthovirus/isolamento & purificação , Bovinos , Doenças dos Bovinos/epidemiologia , Doenças dos Bovinos/transmissão , Doenças dos Bovinos/virologia , Suscetibilidade a Doenças , Febre Aftosa/transmissão , Febre Aftosa/virologia , Doenças das Cabras/epidemiologia , Doenças das Cabras/transmissão , Doenças das Cabras/virologia , Cabras , Incidência , Ovinos , Doenças dos Ovinos/epidemiologia , Doenças dos Ovinos/transmissão , Doenças dos Ovinos/virologia , Suínos , Doenças dos Suínos/epidemiologia , Doenças dos Suínos/transmissão , Doenças dos Suínos/virologiaRESUMO
Foot and mouth disease virus RNA was visualized in infected primary tissue culture cells by in situ PCR incorporating digoxigenin-labeled dUTP. The viral RNA polymerase gene was used as a target for amplification. Infected cells revealed cytoplasmic staining, predominantly perinuclear. The intensity of staining was in proportion to the degree of cytopathology observed and similar to the results obtained using immunoperoxidase staining. The in situ PCR technique for FMDV detection could be applied to formalin-fixed samples and be useful for the study of persistent infections.
Assuntos
Aphthovirus/isolamento & purificação , Reação em Cadeia da Polimerase/métodos , RNA Viral/análise , Animais , Aphthovirus/genética , Sequência de Bases , Células Cultivadas , Primers do DNA , Rim/citologia , Dados de Sequência Molecular , OvinosRESUMO
Bovine spongiform encephalopathy (BSE) is a new disease of cattle first described in the United Kingdom in November 1986. BSE belongs to the scrapie-related group of diseases. The epidemiological studies performed in the United Kingdom demonstrate that the BSE epidemic was caused by feeding cattle with ruminant-derived protein contaminated by a scrapie-like agent. Until June 1994, the disease had been detected in indigenous cattle in Ireland, Switzerland and France. Three cases reported in Germany, two in the Sultanate of Oman, and single cases in the Falkland Islands (Islas Malvinas), Denmark, Portugal and Canada occurred in animals imported from the United Kingdom. Several countries have implemented surveillance programmes analysing the risk factors involved in the epidemic. An analysis of risk factors conducted in Argentina shows that it is highly unlikely that BSE or scrapie exist in the country, or will arise via feed in the future. As a continuation of the analysis of risk factors, a surveillance programme was implemented in the field and in abattoirs. Specialised personnel were trained in the clinical, histopathological and biochemical detection of the disease through a network of laboratories which covered 85% of the total cattle population and 100% of the high-risk group (dairy cows over five years of age). By using a statistical procedure with reference to the bovine population in nine provinces, 1,019 brains from animals belonging to the high-risk group were selected and studied by histopathological and biochemical analyses for BSE detection. The results were negative in all cases. It can be concluded from this analysis (with a sensitivity of detection of 2.95 per 1,000, and 95% statistical confidence) that Argentina may be regarded as BSE-free, and that the importation of infected animals or by-products may represent the sole potential source of introduction of BSE infection into the country in the future.
Assuntos
Encefalopatia Espongiforme Bovina/epidemiologia , Matadouros , Animais , Argentina/epidemiologia , Encéfalo/patologia , Bovinos , Feminino , Masculino , Fatores de RiscoRESUMO
This study was undertaken in order to explore possible sites of foot-and-mouth disease virus (FMDV) persistence during the carrier state. Tissue samples taken from experimentally infected animals at different times post-infection (p.i.) were examined by conventional viral isolation and the polymerase chain reaction (PCR) technique. The analysis of samples from several organs taken from 17 bovines between 3 and 270 days p.i. allowed the following conclusions: 1) Virus present in oesophageal-pharyngeal fluids (OPF) during the carrier state originates in the pharynx as shown by the detection of antisense FMDV RNA by PCR, 2) PCR is more sensitive than standard virus isolation techniques and may be used for the rapid detection of FMDV in specimens obtained during the acute stage of FMD and for identification of persistently infected cattle.
Assuntos
Aphthovirus/isolamento & purificação , Portador Sadio/microbiologia , Doenças dos Bovinos/microbiologia , Febre Aftosa/microbiologia , Animais , Aphthovirus/genética , Southern Blotting/veterinária , Bovinos , DNA Viral/análise , Reação em Cadeia da Polimerase/veterináriaRESUMO
Epidemiological studies conducted in the United Kingdom have revealed the risk factors involved in the epidemic of bovine spongiform encephalopathy (BSE). This has facilitated a detailed study of risk factors associated with the possible introduction of BSE into Argentina. An analysis has been made of the numbers and geographical distribution of cattle in the country, the structure of the Veterinary Services responsible for controlling animal diseases, the way in which cattle and sheep are slaughtered, and the use of slaughter waste in the feed industry. The results of this analysis form the basis of a discussion of whether scrapie or BSE could become endemic in Argentina through contaminated feed or another route. The authors conclude that Argentina may be regarded as free from BSE, and that the importation of infected bovines is the sole potential risk for introduction of BSE in the future.
Assuntos
Encefalopatia Espongiforme Bovina/epidemiologia , Ração Animal/efeitos adversos , Animais , Argentina/epidemiologia , Bovinos , Comércio , Indústria de Laticínios/estatística & dados numéricos , Demografia , Fatores de Risco , Scrapie/epidemiologia , Ovinos , Medicina Veterinária/organização & administração , Medicina Veterinária/estatística & dados numéricosRESUMO
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.