RESUMO
Cattle are broadly deemed a source of Coxiella burnetii; however, evidence reinforcing their role in human infection is scarce. Most published human Q fever outbreaks relate to exposure to small ruminants, notably goats. Anti-phase II C. burnetii IgG and IgM were measured by indirect fluorescent antibody tests in 27 farm and veterinary diagnostic laboratory workers to ascertain whether occupational exposure to cattle aborting due to C. burnetii was the probable source of exposure. Four serological profiles were identified on the basis of anti-phase II IgG and IgM titres. Profile 1, characterised by high IgM levels and concurrent, lower IgG titres (3/27; 11.1%); Profile 2, with both isotypes with IgG titres higher than IgM (2/27; 7.4%); Profile 3 with only IgG phase II (5/27; 18.5%); and Profile 4, in which neither IgM nor IgG were detected (17/27; 63.0%). Profiles 1 and 2 are suggestive of recent C. burnetii exposure, most likely 2.5-4.5 months before testing and, hence, during the window of exposure to the bovine abortions. Profile 3 suggested C. burnetii exposure that most likely predated the window of exposure to aborting cattle, while Profile 4 represented seronegative individuals and, hence, likely uninfected. This study formally linked human Q fever to exposure to C. burnetii infected cattle as a specific occupational hazard for farm and laboratory workers handling bovine aborted material.
RESUMO
Flaviviruses as West Nile virus (WNV), Saint Louis encephalitis virus (SLEV), Ilhéus virus (ILHV), and Rocio virus (ROCV) are previously reported in different Brazilian regions, but studies in Southern Brazil are still scarce. To improve the information regarding flaviviruses in Southern Brazil, horse serum samples were analyzed using RT-qPCR and a commercial ELISA-Ab against WNV followed by PRNT75. All 1000 samples analyzed by real-time RT-PCR resulted negative. The 465 subsampled samples were analyzed by a commercial ELISA-Ab against WNV, and the 18.5% (86/465) positive samples were further analyzed by PRNT75. In the PRNT75, 13/86 and 2/86 horses were positive for SLEV and WNV, respectively. It was observed that 5.8% (13/226) of the farms presented at least one positive animal for SLEV in PRNT75, whereas 0.9% (2/226) for WNV. Apart from the lower seroprevalences identified when compared to data previously reported in other Brazilian regions, our results suggest that public health professionals must be aware of the presence of these potential zoonotic pathogens.
Assuntos
Vírus da Encefalite de St. Louis/isolamento & purificação , Encefalite por Arbovirus/veterinária , Infecções por Flavivirus/veterinária , Doenças dos Cavalos/virologia , Vírus do Nilo Ocidental/isolamento & purificação , Animais , Anticorpos Antivirais/sangue , Brasil/epidemiologia , Vírus da Encefalite de St. Louis/genética , Vírus da Encefalite de St. Louis/imunologia , Encefalite por Arbovirus/sangue , Encefalite por Arbovirus/epidemiologia , Encefalite por Arbovirus/virologia , Infecções por Flavivirus/sangue , Infecções por Flavivirus/epidemiologia , Infecções por Flavivirus/virologia , Geografia , Doenças dos Cavalos/sangue , Doenças dos Cavalos/epidemiologia , Cavalos , RNA Viral/genética , Estudos Soroepidemiológicos , Vírus do Nilo Ocidental/genética , Vírus do Nilo Ocidental/imunologiaRESUMO
Detection of bovine Babesia spp. and Anaplasma marginale is based on the reading of Giemsa-stained blood or organ smears, which can have low sensitivity. Our aim was to improve the detection of bovine Babesia spp. and A. marginale by validating a multiplex PCR (mPCR). We used 466 samples of blood and/or organs of animals with signs and presumptive autopsy findings of babesiosis or anaplasmosis. The primers in our mPCR amplified the rap-1a gene region of Babesia bovis and B. bigemina, and the msp-5 region of A. marginale. We used a Bayesian model with a non-informative priori distribution for the prevalence estimate and informative priori distribution for estimation of sensitivity and specificity. The sensitivity and specificity for smear detection of Babesia spp. were 68.6% and 99.1%, and for A. marginale 85.6% and 98.8%, respectively. Sensitivity and specificity for mPCR detection for Babesia spp. were 94.2% and 97.1%, and for A. marginale 95.2% and 92.7%, respectively. Our mPCR had good accuracy in detecting Babesia spp. and A. marginale, and would be a reliable test for veterinarians to choose the correct treatment for each agent.
Assuntos
Anaplasma marginale/isolamento & purificação , Anaplasmose/diagnóstico , Babesia/isolamento & purificação , Babesiose/diagnóstico , Doenças dos Bovinos/diagnóstico , Anaplasma marginale/genética , Anaplasmose/sangue , Animais , Babesia/genética , Babesiose/sangue , Bovinos , Doenças dos Bovinos/sangue , Reação em Cadeia da Polimerase Multiplex/veterinária , Sensibilidade e Especificidade , UruguaiRESUMO
The Pestivirus genus comprises species that affect animal health and productivity worldwide. Members of the Suidae family are hosts for classical swine fever virus (CSFV), an important pathogen tracked by the World Organization for Animal Health (OIE). However, swine are also susceptible to other pestivirus species that can result in disease or compromise CSFV detection. We searched for pestivirus infection in swine sera collected from 320 backyard pig herds in southern Brazil. We used reverse-transcription PCR primers for Bungowannah virus; atypical porcine pestivirus (APPV); and a panpestivirus pair that detects bovine viral diarrhea virus (BVDV)-1, -2, and HoBi-like pestivirus (HoBiPeV), border disease virus (BDV), and CSFV. Two samples were positive using the panpestivirus primer pair and were classified as BVDV-1d and -2a, respectively. Serum samples were tested for virus neutralization against BVDV-1a, -1b, and -2 strains, resulting in 28 (4.4%) positive samples. Of those, 16 samples had the highest titers against BVDV-1a (2), BVDV-1b (5), and BVDV-2 (9). Our results indicate that Bungowannah virus, APPV, CSFV, BDV, and HoBiPeV have not been circulating in these specific backyard swine populations. However, ruminant pestiviruses were detected and must be considered in future pestivirus control programs conducted in Brazil.
Assuntos
Infecções por Pestivirus/veterinária , Pestivirus/isolamento & purificação , Doenças dos Suínos/virologia , Animais , Brasil/epidemiologia , Vírus da Febre Suína Clássica , Pestivirus/classificação , Infecções por Pestivirus/epidemiologia , Infecções por Pestivirus/virologia , Reação em Cadeia da Polimerase , Inquéritos e Questionários , Suínos , Doenças dos Suínos/epidemiologiaRESUMO
A retrospective study compiling cases of feline lymphoma diagnosed during 12 years (2004-2016) in Southern Brazil was performed. A total of 125 cases of lymphoma diagnosed in cats were reviewed, and information including age, breed, sex and tumour topography were collected. FeLV and FIV immunohistochemical tests were performed, as well as immunophenotyping of lymphomas. The alimentary form represented the most common presentation (42/125), followed by mediastinal lymphoma (35/125). Out of 125 cases, 79 presented positive retroviral immunostaining in tumour tissue (52 FeLV alone, 14 FIV alone and 13 presented FIV and FeLV co-infections), 66/125 of the cases were of T-cell origin and 59/125 of the cases were of B-cell origin. The median age of cats with T-cell lymphoma was 120 months (10-240 months), and 60 months (6-204 months) for cats with B-cell lymphoma. The most frequent alimentary tumour presentation was the enteropathy-associated T-cell lymphoma (type 1), and the major type of mediastinal tumour observed was diffuse large B-cell lymphoma. Considering only mediastinal and alimentary lymphomas (n = 77), the prevalence of mediastinal lymphoma in FeLV-positive cats was 2.21 times higher than the prevalence of this type of tumour in FeLV-negative cats (P = .036). Mediastinal lymphoma was more frequently observed in younger cats, and the prevalence of mediastinal tumours in these animals was 3.06 times higher than the prevalence of this tumour form in old cats (P = .0125). The present study indicates that retroviral infections still play an important role in the development of feline lymphomas in southern Brazil.
Assuntos
Doenças do Gato/patologia , Linfoma/veterinária , Animais , Brasil/epidemiologia , Doenças do Gato/epidemiologia , Gatos , Feminino , Imuno-Histoquímica/veterinária , Linfoma/epidemiologia , Linfoma/patologia , Masculino , Estudos RetrospectivosRESUMO
Brazil is the fourth largest producer and exporter of pork in the world, but has never reported yet the occurrence of some economically important diseases such as porcine reproductive and respiratory syndrome (PRRS) and porcine epidemic diarrhea (PED). Most of the swine farms in Brazil are characterized by intensive production being part of large integrated companies, where biosecurity practices help to prevent the introduction and spread of disease-causing infectious agents. The assessment of biosecurity in farms is not straightforward because of the large number of practices that constitute an on-farm biosecurity program. It is therefore necessary to combine the measurement of several parameters in order to characterize the level of biosecurity on a given farm. Thus, the objective of the study was to develop a biosecurity score to estimate the biosecurity level (theta or θ) in swine farms using the item response theory (IRT) and explore the relationship between the scores and independent variables. The IRT is a latent trait method extensively used in other fields, and offers the advantage to quantify the latent trait, here the biosecurity level, and to identify the practices that discriminate the farms avoiding the use of extensive questionnaires and redundant questions. In this study, 604 farms were evaluated in the main swine production regions of the state of Rio Grande do Sul, Brazil. Thirty-five practices were considered in order to quantify the biosecurity level on a given farm. After a recursive process 14 practices were selected to compose the biosecurity score to estimate the biosecurity level (θ). The variables identified with greater capacity of distinguishing the farms as to their biosecurity level were if the farm has 'feed bin outside of the barn limit (external feed loading)', has 'perimetral fence around the farm or barn', and if 'transit of trucks inside the farm is prohibited'. The biosecurity level was associated with some independent variables, e.g. the farm operation type, the integrated company and some owner characteristics. In addition, the results demonstrated that biosecurity practices related to management (internal biosecurity) are adopted with higher frequency compared to segregation and sanitation practices (external biosecurity). The IRT model proved useful and valid to estimate the biosecurity level in swine farms. Moreover, the biosecurity score described here has a relatively low number of items, which makes the application of this tool easier and faster compared to other previously described biosecurity assessment.
Assuntos
Criação de Animais Domésticos/métodos , Doenças dos Suínos/prevenção & controle , Animais , Brasil/epidemiologia , Controle de Doenças Transmissíveis/métodos , Controle de Doenças Transmissíveis/normas , Fazendas , Fatores de Risco , Suínos , Doenças dos Suínos/epidemiologiaRESUMO
Backyard pig populations are not monitored for influenza A virus (IAV) in Brazil and there are limited data about seroprevalence and risk factors in these populations. Our goal was to assess possible factors associated with IAV seroprevalence in backyard pig populations using an indirect ELISA protocol based on a recombinant nucleoprotein. Following the IAV screening using NP-ELISA, subtype-specific serology based on hemagglutination inhibition (HI) assay of the ELISA-positive pigs was conducted. The survey comprised a total of 1,667 sera samples collected in 2012 and 2014 in 479 holdings and the estimated seroprevalence was 5.3% (3.84%-7.33%) and 2.3% (1.34%-3.71%) in the respective years. In both years, H1N1pdm09 was the most prevalent subtype. The multivariable analysis showed main factors such as "age," "sex," "number of suckling pigs" and "neighbours raising pigs" that presented the greatest effect on IAV seroprevalence in these pig populations. These factors may be associated with the low biosecurity measures and management of backyard holdings. In addition, the low IAV seroprevalences found in these backyard pig populations could be related to a low number of animals in each pig holding and low animal movement/replacement that do not favour IAV transmission dynamics. This low frequency of H1N1pdm09 seropositive pigs could also be due to sporadic human-to-pig transmission of what is now a human seasonal influenza A virus; however, these factors should be explored in future studies. Herein, these results highlight the importance of IAV continued surveillance in backyard pig holdings, since it is poorly known which IAVs are circulating in these populations and the risk they could pose to public health and virus transmission to commercial farms.
Assuntos
Vírus da Influenza A/isolamento & purificação , Infecções por Orthomyxoviridae/veterinária , Doenças dos Suínos/virologia , Animais , Brasil/epidemiologia , Ensaio de Imunoadsorção Enzimática , Feminino , Masculino , Infecções por Orthomyxoviridae/epidemiologia , Infecções por Orthomyxoviridae/virologia , Estudos Soroepidemiológicos , Suínos , Doenças dos Suínos/epidemiologiaRESUMO
Biosecurity is defined as the set of practices carried out to prevent the introduction and spread of infectious agents in a herd. These practices are essential in swine production, especially for highly infectious agents such as porcine reproductive and respiratory syndrome virus (PRRSv). Even with years of research and experience over the last three decades, PRRSv is still causing productivity losses and is the major health problem affecting the global swine industry. Despite knowledge of the various ways in which the virus can be transmitted from one herd to another (e.g. animals, semen, truck, air, and people), determining the most frequent ways in which the virus is transmitted in the field is difficult. A systematic approach to assess vulnerabilities at a herd level related to PRRSv transmission could help producers prioritize biosecurity practices to reduce or avoid the occurrence of outbreaks. The aim of this study was to develop a biosecurity vulnerability score that represents the relative vulnerability of swine breeding herds to the introduction of PRRSv. To create the biosecurity vulnerability score (outcome), a multi-criteria decision analysis methodology was used to rank and quantify biosecurity practices based on expert opinion. To validate the biosecurity vulnerability score, a survey of biosecurity practices and PRRS outbreak histories in 125 breed-to-wean herds in the U.S. swine industry was used. Data on the frequency of PRRS outbreaks was used to test the hypothesis that biosecurity vulnerability scores were different between farms that have a low incidence of PRRS outbreaks, compared to farms that have a high incidence. In the two databases used, the scores consistently showed that farms with higher scores have a higher frequency of PRRS outbreaks. In the first validation, farms that had never had an outbreak investigation before had a significant (p < 0.02) lower score (0.29; 0.21-0.37) when compared to farms that had 2 or more outbreaks (0.43; 0.39-0.46). In the second, the farms of the control group also had significant (p < 0.004) lower scores (0.30; 0.27-0.33) compared to the case group (0.35; 0.33-0.38). Also, the results suggest that events related to swine movements, transmission by air and water, and people movements should be prioritized. The biosecurity vulnerability scores may be useful to assess vulnerabilities on biosecurity protocols in order to reduce the frequency of PRRS outbreaks and may help producers and veterinarians prioritize investments in improving biosecurity practices over time.
Assuntos
Síndrome Respiratória e Reprodutiva Suína/etiologia , Vírus da Síndrome Respiratória e Reprodutiva Suína , Criação de Animais Domésticos/métodos , Animais , Surtos de Doenças/prevenção & controle , Surtos de Doenças/veterinária , Suscetibilidade a Doenças/veterinária , Feminino , Síndrome Respiratória e Reprodutiva Suína/transmissão , Gravidez , Reprodutibilidade dos Testes , Medição de Risco , Fatores de Risco , Inquéritos e Questionários , SuínosRESUMO
Avaliaram-se os resultados de testes para diagnóstico da brucelose e tuberculose bovinas objetivando analisar a distribuição de positividade e características de performance do programa de controle. A análise utilizou como dados secundários todos os resultados de testes para diagnóstico realizados em bovinos no ano de 2008 no estado do Rio Grande do Sul (RS) por médicos veterinários habilitados para atuação no âmbito do Programa Nacional de Controle e Erradicação de Brucelose e Tuberculose Animal. Os dados foram estatisticamente ajustados para minimizar os efeitos de valores extremos e de dados faltantes. Os testes alcançaram 66,80% dos 497 municípios do RS e incluíram a participação de 165 médicos veterinários habilitados. 40,21% dos testes foram realizados nos meses de abril, setembro e outubro, sendo que em 73,90% dos estabelecimentos foram realizados testes para ambas as enfermidades. No caso da brucelose verificou-se que foram testados 35.289 animais, com uma frequência de positivos de 0,25%, enquanto a frequência de estabelecimentos positivos entre os 3.406 testados foi 0,94%. Fêmeas apresentaram frequência de positividade mais elevada (0,29%, de 26.724 testadas) do que machos (0,13%, de 5.235 testados). Animais entre 48-60 meses de idade apresentaram chance de positividade superior às demais faixas etárias (Razão de Chances (RC) =2,63; IC 95%=1,63-4,26). Animais de aptidão leiteira representaram 62,66% dos animais testados, e apresentaram maior chance de positividade do que animais de corte (RC=2,32; IC 95%=1,38-3,90). Adicionalmente, 73,74% dos estabelecimentos testados eram dedicados à produção de leite. Já no caso da tuberculose foram testados 62.149 animais distribuídos em 5.151 propriedades, com frequência de positivos de 0,87% e 3,13%, respectivamente. A chance de positividade aumentou com a idade, sendo que animais com idade acima de 48 meses de idades apresentaram valores superiores aqueles verificados em animais mais jovens (RC=2,07; IC 95%=1,73-2,48). 59,74% dos animais testados eram de aptidão leiteira, os quais apresentaram mais chance de serem positivos do que aqueles de corte (RC=5,03; IC 95%=4,09-6,94). Propriedades leiteiras representaram 78,50% da totalidade dos testes para tuberculose. A análise comparativa do presente trabalho com estudos precedentes de prevalência da brucelose sugere que as ações de controle em curso têm sido efetivas na redução da prevalência da enfermidade no RS. Por outro lado, as informações obtidas no âmbito da tuberculose podem ser indicadoras da condição desta enfermidade, especialmente pela inexistência de estudos de prevalência realizados há menos de 30 anos. Adicionalmente, conclui-se que a utilização de dados secundários, desde que devidamente ajustados, pode ser uma ferramenta eficaz na gestão de programas de saúde animal e em sistemas de monitoramento e vigilância.(AU)
Results of tests for the diagnosis of bovine brucellosis and tuberculosis were evaluated aiming to analyze the distribution of positivity and characteristics of performance of the control program. The analysis used as secondary data the results of all diagnostic tests of bovines executed in 2008 in the state of Rio Grande do Sul (RS) by veterinarians authorized to operate under the National Program for Control and Eradication of Animal Brucellosis and Tuberculosis. The data were statistically adjusted to minimize the effect of outliers and missing data. The tests achieved 66.80% of the 497 municipalities in the RS and included the participation of 165 authorized veterinarians. 40.21% of tests were carried out in the months of April, September and October, and in 73.90% of establishments had tests performed for both diseases. In the case of brucellosis it appeared that 35,289 animals were tested, with positivity of 0.25%, while the frequency of positive holdings among the 3,406 tested was 0.94%. Females had higher positivity rate (0.29% of 26,724 tested) than males (0.13% of 5,235 tested). Animals between 48-60 months of age presented higher chance of positivity compared to other age groups (Odds Ratio (OR) = 2.63; CI 95% = 1.63 - 4.26). Dairy cattle represented 62.66% of tested animals, which were more likely to appear as positive than beef animals (OR = 2.32; CI 95% = 1.38 - 3.90). In addition, 73.74% of the tested holdings were dairy ones. In the case of tuberculosis, 62,149 animals were tested, distributed in 5,151 holdings, with positivity of 0.87% and 3.13%, respectively. The chance of positivity increased with age, being that animals older than 48 months presented higher values compared to ââthose found in younger animals (OR = 2.07; CI 95% = 1.73 - 2.48). Dairy cattle represented 59.74% of tested animals, which were more likely to be positive than beef ones (OR = 5.03; CI 95% = 4.09 - 6.94). Dairy holdings were 78.50% of all the tests for tuberculosis. The comparative analysis of this study with previous studies on brucellosis prevalence suggested that current control measures have been effective in reducing the prevalence of this disease in RS. On the other hand, information obtained on tuberculosis can be indicators of the condition of this disease, especially in the lack of prevalence studies carried out in the last 30 years. Finally, it is concluded that the use of secondary data, if properly adjusted, can be an effective tool in the management of animal health programs and monitoring and surveillance systems.(AU)