RESUMO

Bovine neosporosis is a globally important disease, causing abortions and significant economic losses. In Brazil, studies on neosporosis in cattle are few and based on limited samples and/or from limited areas. We aimed to determine the herd and animal levels seroprevalence and associated factors for Neospora caninum infections in cattle from the state of Paraíba, Northeastern Brazil, using a planned sampling. Herds (n = 434) and cows aged ≥24 months (n = 1891) were randomly selected, and serum samples were tested with the immunofluorescence antibody test (IFAT) using as cut-off point the antibody titer 200. Herd-level and animal-level seroprevalences were 17.8% (95% CI = 14.3%-21.8%) and 18.1% (95% CI = 14.7%-22.1%), respectively. The factors associated with N. caninum infection were farm located in the Sertão mesoregion (Prevalence ratio [PR] = 2.37), mixed production (PR = 1.64), herd size of 34-111 animals (PR = 3.50) and herd size >111 animals (PR = 6.14). The results indicate high N. caninum circulation in the bovine population of the state of Paraíba, semiarid of Brazil, mainly in the Sertão mesoregion, where the highest apparent herd and animal-level prevalences of positive herds were identified. Control strategies should be adopted to mitigate the impact of disease on cattle production, as well as it's suggested the encouragement of conducting surveys in wildlife from Caatinga biome, mainly canids, to provide information on the importance of these animals on the epidemiology of bovine neosporosis.

Assuntos

RESUMO

The aim of this study was to describe the prevalence of Neospora caninum based on the detection of specific antibodies in bulk tank milk (BTM) from dairy cattle farms in the Mar y Sierras Basin by using an enzyme-linked immunosorbent assay (ELISA). A total of 98 BTM samples from 49 dairy farms were collected during autumn and spring of 2019. Additionally, 147 paired individual milk and serum samples were collected from two dairy farms to assess the prevalence within-herd by ELISA and indirect fluorescent antibody test (IFAT, serum samples). Additionally, 12 individual serum samples were also assessed to test the agreement between IFAT and ELISA (total serum samples 159). Noteworthy, 100 and 91.84% of 49 dairy farms were positive in the BTM in autumn and spring, respectively. For the within-herd individual samples, a good agreement between serum and milk results was obtained for ELISA and IFAT (0.86-0.90). This is the first study in Argentina in which milk samples were tested to determine the N. caninum infection status at herd and within-herd levels in dairy farms, providing a base for further research.

Assuntos

RESUMO

Neosporose e toxoplasmose são doenças de importância na esfera reprodutiva e em saúde pública. Dados de soroprevalência destes protozoários em regiões de importante cadeia produtiva de bovinos no Brasil, como a região Sul, são necessários para compreender a extensão dos problemas causados por estas enfermidades, bem como melhorar o emprego de medidas profiláticas e de controle. Os resultados do levantamento sorológico realizado por este estudo, pela reação de Imunofluorescência Indireta (IFI) para detecção de anticorpos anti-T. gondii e anti-N. caninum, apontaram animais positivos para infecção por T. gondii (7,2%) e N. caninum (7,6%), abaixo das citadas na literatura no Estado do Rio Grande do Sul, que parece apresentar prevalências menores quando comparado com outras regiões do Brasil, caracterizando uma disseminação moderada destes Patógenos.(AU)

Neosporosis and toxoplasmosiss are diseases of importance in the reproductive sphere and public health. Seroprevalence data for these protozoa in regions with major bovine productive chains in Brazil, such as the South, are necessary to understand the extent of the problems caused by these diseases, as well as to improve the use of prophylactic and control measures. The results of the serological survey carried out by this study, using the Indirect Immunofluorescence (IFI) reaction to detect antibodies against T. gondii and anti-N. caninum, showed positive animals for infection by T. gondii (7.2%) and N. caninum (7,6%), below those mentioned in the literature in the State of Rio Grande do Sul, which seems to have lower prevalences when compared to other regions of Brazil, characterizing moderate dissemination of these pathogens.(AU)

La neosporosis y la toxoplasmosis son enfermedades de importancia en el ámbito reproductivo y en la salud pública. Los datos de seroprevalencia de estos protozoos en regiones con una importante cadena productiva bovina en Brasil, como el Sur, son necesarios para comprender la magnitud de los problemas causados por estas enfermedades, así como para mejorar el uso de medidas profilácticas y de control. Los resultados de la encuesta serológica realizada por este estudio, utilizando la reacción de inmunofluorescencia indirecta (IFI) para detectar anticuerpos contra T. gondii y anti-N. caninum, mostraron animales positivos para infección por T. gondii (7,2%) y N. caninum (7,6%), por debajo de los mencionados en la literatura en el estado de Rio Grande do Sul, que parece tener prevalencias menores en comparación con otras regiones de Brasil, caracterizando una diseminación moderada de estos agentes.(AU)

Assuntos

RESUMO

Neosporose e toxoplasmose são doenças de importância na esfera reprodutiva e em saúde pública. Dados de soroprevalência destes protozoários em regiões de importante cadeia produtiva de bovinos no Brasil, como a região Sul, são necessários para compreender a extensão dos problemas causados por estas enfermidades, bem como melhorar o emprego de medidas profiláticas e de controle. Os resultados do levantamento sorológico realizado por este estudo, pela reação de Imunofluorescência Indireta (IFI) para detecção de anticorpos anti-T. gondii e anti-N. caninum, apontaram animais positivos para infecção por T. gondii (7,2%) e N. caninum (7,6%), abaixo das citadas na literatura no Estado do Rio Grande do Sul, que parece apresentar prevalências menores quando comparado com outras regiões do Brasil, caracterizando uma disseminação moderada destes Patógenos.

Neosporosis and toxoplasmosiss are diseases of importance in the reproductive sphere and public health. Seroprevalence data for these protozoa in regions with major bovine productive chains in Brazil, such as the South, are necessary to understand the extent of the problems caused by these diseases, as well as to improve the use of prophylactic and control measures. The results of the serological survey carried out by this study, using the Indirect Immunofluorescence (IFI) reaction to detect antibodies against T. gondii and anti-N. caninum, showed positive animals for infection by T. gondii (7.2%) and N. caninum (7,6%), below those mentioned in the literature in the State of Rio Grande do Sul, which seems to have lower prevalences when compared to other regions of Brazil, characterizing moderate dissemination of these pathogens.

La neosporosis y la toxoplasmosis son enfermedades de importancia en el ámbito reproductivo y en la salud pública. Los datos de seroprevalencia de estos protozoos en regiones con una importante cadena productiva bovina en Brasil, como el Sur, son necesarios para comprender la magnitud de los problemas causados por estas enfermedades, así como para mejorar el uso de medidas profilácticas y de control. Los resultados de la encuesta serológica realizada por este estudio, utilizando la reacción de inmunofluorescencia indirecta (IFI) para detectar anticuerpos contra T. gondii y anti-N. caninum, mostraron animales positivos para infección por T. gondii (7,2%) y N. caninum (7,6%), por debajo de los mencionados en la literatura en el estado de Rio Grande do Sul, que parece tener prevalencias menores en comparación con otras regiones de Brasil, caracterizando una diseminación moderada de estos agentes.

Assuntos

RESUMO

The aim of this study was to describe bovine neosporosis in dairy cattle from the Sierra region, Ecuador. A case-control study was performed on 841 dairy cattle from 5 dairy herds. The overall seroprevalence was 23.4% having significant association between abortion and seropositivity (p < .05). Additionally, 46 fetuses were recovered from a local slaughterhouse to evaluate the frequency of vertical transmission. Seventeen and 3 fetuses were positive by PCR and had compatible histopathological lesions, respectively. N. caninum infection must be considered as a relevant cause of reproductive losses in Ecuador.

Assuntos

RESUMO

Neosporosis is one of the leading causes of abortion in cattle worldwide, posing a great economic burden on cattle producers. The aim of this study was to determine the national seroprevalence and putative risk factors of Neospora caninum (N. caninum) in dairy cattle in Uruguay. A cross-sectional study was carried out. Herds were stratified by size (1-50, 51-250, and >250 cattle) and up to 60 dairy cows per herd were randomly selected. Four thousand two hundred twenty-three serum samples from 102 dairy herds were analyzed by indirect ELISA test, under the manufacturer's recommendations. In addition, the herdsman was surveyed and a population study was carried out. The in degree data, geographical coordinates, and seroprevalence of bovine viral diarrhea, enzootic bovine leukemia and infectious bovine rhinotracheitis were available for each herd. A sampling design was used to estimate population seroprevalence of N. caninum. In order to determine the factors associated with the disease, herds with an intra-herd seroprevalence over 20% were considered as case herds. Seroprevalence of N. caninum was 22.3% (95% CI: 18.7-25.9 %) and 96.0% (95% CI: 92.1-99.8%) at the animal and herd level, respectively. The number of dogs on the dairy farms were associated with infection levels (OR: 1.43, 95% CI: 1.02 to 2.03). It was concluded that N. caninum is endemic in the country, and is spreading over dairy herds. Although this study showed evidence that the number of dogs were associated with high levels of infection, more studies should be conducted, to better understand the epidemiology of the disease and thus develop efficient control measures.

Assuntos

RESUMO

Neospora caninum is one of the main infectious agents that cause reproductive disorders in cattle. However, knowledge about the prevalence and causal factors of bovine neosporosis is needed in order to establish control measures. The purpose of this study was to estimate the pooled prevalence and determine the risk factors of bovine neosporosis using meta-analytic methods. Searches for data on N. caninum seroprevalence and potential risk factors were conducted in the PubMed, LILACS, and SciElo databases. The random effects model was used for the meta-analysis of the included studies. The pooled prevalence of N. caninum in cattle was 24% (95% confidence interval (CI), 19-29) in North and Central America, 24% (95% CI, 20-28) in South America, 18% (95% CI, 14-21) in Asia, 15% (95% CI, 12-18) in Europe, 13% (95% CI, 11-16) in Africa, and 8% (95% CI, 4-14) in Oceania. A significant correlation was found between N. caninum infection and abortion in cows (odds ratio (OR) = 2.66, 95% CI, 1.97-3.59). The following risk factors were signicantly associated with N. caninum seroprevalence: presence of dogs on the farm (OR = 2.84; 95% CI, 1.40-5.80) and the type of cattle production system, with dairy cattle being more susceptible to bovine neosporosis (OR = 1.60; 95% CI, 1.16-2.19) than beef cattle. The adoption of measures to prevent the dissemination of N. caninum in cattle herds is suggested, aiming to reduce the economic losses incurred to the dairy and beef industry.

Assuntos

RESUMO

We carried out an inter-laboratory trial to compare the serological tests commonly used for the detection of specific Neospora caninum antibodies in cattle in Ibero-American countries. A total of eight laboratories participated from the following countries: Argentina (n = 4), Brazil (n = 1), Peru (n = 1), Mexico (n = 1), and Spain (n = 1). A blind panel of well-characterized cattle sera (n = 143) and sera representative of the target population (n = 351) was tested by seven in-house indirect fluorescent antibody tests (IFATs 1-7) and three enzyme-linked immunosorbent assays (ELISAs 1-3; two in-house and one commercial). Diagnostic performance of the serological tests was calculated and compared according to the following criteria: (1) the "Pre-test information," which uses previous epidemiological and serological data; (2) the "Majority of tests," which classifies a serum as positive or negative according to the results obtained by most tests evaluated. Unexpectedly, six tests showed either sensitivity (Se) or specificity (Sp) values lower than 90%. In contrast, the best tests in terms of Se, Sp, and area under the ROC curve (AUC) values were IFAT 1 and optimized ELISA 1 and ELISA 2. We evaluated a high number of IFATs, which are the most widely used tests in Ibero-America. The significant discordances observed among the tests regardless of the criteria employed hinder control programs and urge the use of a common test or with similar performances to either the optimized IFAT 1 and ELISAs 1 and 2.

Assuntos

RESUMO

Neosporosis is a parasitic disease caused by the protozoan Neospora caninum which results in major economic losses for cattle breeding due to abortion and other reproductive disorders. Gerbils (Meriones unguiculatus) are commonly used as experimental models for neosporosis due to their high susceptibility to N. caninum infection, both by oocysts ingestion as by tachyzoites/bradyzoites parenteral inoculation. However, the risk of transmission by tachyzoites ingestion is not fully elucidated. In this study, infection of neonate gerbils by N. caninum (NC-1 strain) tachyzoites inoculated by the oral route and the parasite distribution in gerbils' tissues were evaluated by protozoan DNA detection. Seventeen neonate gerbils, aged 4-5 days, were inoculated with 4x105 tachyzoites by the oral route and one gerbil was kept as uninfected control. N. caninum DNA was detected in 100% of the inoculated gerbils, showing that the oral route is effective as a potential route of infection of neonates by N. caninum tachyzoites. N. caninum DNA was reported in all organs evaluated (heart, lungs, kidneys, liver, spleen and brain), with different frequencies. These results showed systemically distributed infection of neonate gerbils after oral inoculation of tachyzoites.(AU)

Neosporose é uma doença parasitária causada pelo protozoário Neospora caninum e resulta em grandes perdas econômicas para a bovinocultura, o que se deve a abortos e outras desordens reprodutivas. Gerbils (Meriones unguiculatus) são comumente utilizados como modelos experimentais para neosporose, devido a sua alta susceptibilidade à infecção por N. caninum, seja pela ingestão de oocistos ou pela inoculação parenteral de taquizoítos/bradizoítos. Porém, o risco de transmissão pela ingestão de taquizoítos não está totalmente elucidado. Neste estudo, foram avaliadas a infecção de gerbils neonatos por taquizoítos de N. caninum (cepa NC-1) inoculados por via oral e a distribuição do parasita nos tecidos desses gerbils, através da detecção de DNA do protozoário. Dezessete gerbils neonatos, com idade de 4-5 dias, foram inoculados com 4x105 taquizoítos por via oral e um gerbil foi mantido como controle não-infectado. DNA de N. caninum foi detectado em 100% dos gerbils inoculados, demonstrando a eficácia da via oral como potencial rota de infecção de neonatos por taquizoítos de N. caninum. DNA de N. caninum foi encontrado, em diferentes frequências, em todos os órgãos avaliados (coração, pulmões, rins, fígado, baço e cérebro). Esses resultados demonstraram infecção sistêmica dos gerbils neonatos após a inoculação oral de taquizoítos.(AU)

Assuntos

RESUMO

ABSTRACT: Neosporosis is a parasitic disease caused by the protozoan Neospora caninum which results in major economic losses for cattle breeding due to abortion and other reproductive disorders. Gerbils (Meriones unguiculatus) are commonly used as experimental models for neosporosis due to their high susceptibility to N. caninum infection, both by oocysts ingestion as by tachyzoites/bradyzoites parenteral inoculation. However, the risk of transmission by tachyzoites ingestion is not fully elucidated. In this study, infection of neonate gerbils by N. caninum (NC-1 strain) tachyzoites inoculated by the oral route and the parasite distribution in gerbils' tissues were evaluated by protozoan DNA detection. Seventeen neonate gerbils, aged 4-5 days, were inoculated with 4x105 tachyzoites by the oral route and one gerbil was kept as uninfected control. N. caninum DNA was detected in 100% of the inoculated gerbils, showing that the oral route is effective as a potential route of infection of neonates by N. caninum tachyzoites. N. caninum DNA was reported in all organs evaluated (heart, lungs, kidneys, liver, spleen and brain), with different frequencies. These results showed systemically distributed infection of neonate gerbils after oral inoculation of tachyzoites.

RESUMO: Neosporose é uma doença parasitária causada pelo protozoário Neospora caninum e resulta em grandes perdas econômicas para a bovinocultura, o que se deve a abortos e outras desordens reprodutivas. Gerbils (Meriones unguiculatus) são comumente utilizados como modelos experimentais para neosporose, devido a sua alta susceptibilidade à infecção por N. caninum, seja pela ingestão de oocistos ou pela inoculação parenteral de taquizoítos/bradizoítos. Porém, o risco de transmissão pela ingestão de taquizoítos não está totalmente elucidado. Neste estudo, foram avaliadas a infecção de gerbils neonatos por taquizoítos de N. caninum (cepa NC-1) inoculados por via oral e a distribuição do parasita nos tecidos desses gerbils, através da detecção de DNA do protozoário. Dezessete gerbils neonatos, com idade de 4-5 dias, foram inoculados com 4x105 taquizoítos por via oral e um gerbil foi mantido como controle não-infectado. DNA de N. caninum foi detectado em 100% dos gerbils inoculados, demonstrando a eficácia da via oral como potencial rota de infecção de neonatos por taquizoítos de N. caninum. DNA de N. caninum foi encontrado, em diferentes frequências, em todos os órgãos avaliados (coração, pulmões, rins, fígado, baço e cérebro). Esses resultados demonstraram infecção sistêmica dos gerbils neonatos após a inoculação oral de taquizoítos.

RESUMO

Neospora caninum is a protozoan parasite that causes abortion and important economic losses in cattle worldwide. The accurate diagnosis of neosporosis is essential for management and control measures. The aims of this study were: i) to evaluate the performance of an in-house enzyme-linked immunosorbent assay based on the 38 kDa native antigen (p38-ELISA) to diagnose bovine neosporosis in Argentina using a well- characterized local sera panel from experimentally infected and naturally exposed cattle and ii) to compare the diagnostic performance and agreement of three N. caninum serological tests: p38-ELISA, indirect fluorescence antibody test (IFAT) and immunoblotting (IB) using the same sera panel. Serum samples testing either positive or negative by IFAT and IB were considered "Relative Standards of Comparison" (RSC) and used for p38-ELISA evaluation. Receiver operating characteristics analysis revealed that p38-ELISA was highly accurate (area under the curve= 0.982) according to RSC with a cut-off index of 0.0905. Relative sensitivity and specificity of p38-ELISA were 97.8 % and 99.5 %, respectively and agreement between RSC and p38-ELISA was almost perfect (k= 0.97). The evaluation and performance comparison of serological tests were performed according to the definition of gold standard based on the decision of the "majority of tests". All tests displayed high sensitivity and specificity values (greater than 95 %); and excellent agreement. This study describes the accurate performance of p38-ELISA evaluated locally and the highly accurate diagnostic performance of the studied tests for the detection of anti-N. caninum antibodies in cattle from Argentina.

Neospora caninum es un parásito protozoo responsable de abortos y pérdidas económicas en bovinos. La realización de un diagnóstico serológico preciso y con resultados comparables obtenidos por diferentes pruebas contribuye al manejo de este problema y a encarar medidas de control. Los objetivos del presente trabajo fueron los siguientes: 1) evaluar en Argentina una prueba de enzimoinmunoensayo in-house con el antígeno nativo de 38 kDa de N. caninum (ELISA-p38) para el diagnóstico de la neosporosis bovina, utilizando un panel de sueros locales bien caracterizados, procedentes de bovinos infectados de modo experimental o naturalmente expuestos; 2) comparar el desempeño y establecer el nivel de concordancia de tres pruebas serológicas para la detección de N. caninum, ELISA-p38, inmunofluorescencia indirecta (IFI) e inmunoblot (IB), con el mismo panel de sueros. Los sueros que resultaron positivos o negativos a IFI e IB fueron considerados como estándares relativos de comparación (ERC) para evaluar la prueba de ELISA-p38. El análisis de característica operativa del receptor determinó que la prueba de ELISA-p38 fue altamente precisa (área bajo la curva= 0,982) usando el punto de corte 0,0905. La sensibilidad y especificidad relativa del ELISA-p38 fue 97,8 % y 99,5 %, respectivamente, con una concordancia casi perfecta (k= 0,97) respecto del ERC. La comparación del desempeño de las pruebas se realizó usando como gold standard el criterio de la decisión de la "mayoría de las pruebas". Las pruebas exhibieron altos valores de sensibilidad y especificidad (mayores del 95 %) y excelente concordancia. Este trabajo describe un buen desempeño de la prueba de ELISA-p38 evaluada localmente y adecuada performance diagnóstica de las pruebas serológicas analizadas para la detección de anticuerpos anti N. caninum en bovinos de Argentina.

Assuntos

RESUMO

Neospora caninum is a protozoan parasite that causes abortion and important economic losses in cattle worldwide. The accurate diagnosis of neosporosis is essential for management and control measures. The aims of this study were: i) to evaluate the performance of an in-house enzyme-linked immunosorbent assay based on the 38kDa native antigen (p38-ELISA) to diagnose bovine neosporosis in Argentina using a well- characterized local sera panel from experimentally infected and naturally exposed cattle and ii) to compare the diagnostic performance and agreement of three N. caninum serological tests: p38-ELISA, indirect fluorescence antibody test (IFAT) and immunoblotting (IB) using the same sera panel. Serum samples testing either positive or negative by IFAT and IB were considered "Relative Standards of Comparison" (RSC) and used for p38-ELISA evaluation. Receiver operating characteristics analysis revealed that p38-ELISA was highly accurate (area under the curve= 0.982) according to RSC with a cut-off index of 0.0905. Relative sensitivity and specificity of p38-ELISA were 97.8% and 99.5%, respectively and agreement between RSC and p38-ELISA was almost perfect (k= 0.97). The evaluation and performance comparison of serological tests were performed according to the definition of gold standard based on the decision of the "majority of tests". All tests displayed high sensitivity and specificity values (greater than 95%); and excellent agreement. This study describes the accurate performance of p38-ELISA evaluated locally and the highly accurate diagnostic performance of the studied tests for the detection of anti-N. caninum antibodies in cattle from Argentina.

Assuntos

RESUMO

Objetivou-se, no presente estudo, pesquisar a prevalência de anticorpos anti-Neospora caninum em 812 amostras de soros sangüíneos de bovinos leiteiros procedentes de propriedades rurais de sete municípios das microrregiões de Itapecuru-Mirim, Médio Mearim e Presidente Dutra, estado do Maranhão, Brasil. Para o cálculo do tamanho da amostra, considerou-se um soroprevalência de 34,7 por cento para N. caninum, com erro máximo de 9,5 por cento e intervalo de confiança de 95 por cento. Para a detecção da presença de anticorpos da classe IgG, utilizou-se a técnica de Imunofluorescência Indireta (IFI), com ponto de corte 1:200, usando como antígeno, taquizoítos da cepa NC-1, mantida em cultura celular no Laboratório de Diagnóstico das Parasitoses dos Animais da Escola de Medicina Veterinária da UFBA. Do total de amostras analisadas, encontrou-se uma prevalência de 50,74 por cento. Os títulos variaram de 1:200 a 1:6400, assim distribuídos: 108 (26,21 por cento) amostras de soro apresentaram título de 1:200; 132 (32,04 por cento) 1:400; 94 (22,81 por cento) 1:800; 46 (11,16 por cento) 1:1600; 23 (5,58 por cento) 1:3200 e nove (2,18 por cento) com títulos de 1:6400. Dentre as microrregiões, a Itapecuru-Mirim apresentou o menor percentual de animais soropositivos (20,69 por cento) e Presidente Dutra o maior (47,66 por cento). Com relação à variável sexo, observou-se maior prevalência de sororreagentes nas fêmeas (46,80 por cento) do que nos machos (52,46 por cento). Não se verificou diferença significativa (P>0,05) para as variáveis microrregiões, sexo e idade. Conclui-se que os bovinos leiteiros das regiões estudadas estão expostos à infecção por N. caninum.(AU)

The objective in the present study was to research the prevalence of anti-Neospora caninum in 812 samples of blood serum of dairy cattle from farms of seven municipalities of microrregions of Itapecuru-Mirim, Middle Mearim and President Dutra, state of Maranhão, Brazil. For the calculation of sample size, it was considered a seroprevalence of 34.7 percent for N. caninum, with a maximum error of 9.5 percent and a confidence interval of 95 percent. To detect antibodies, it was used the technique of Indirect Immunofluorescence (IFI), with the cut-off of 1:200, using as antigen, tachyzoites strain NC-1, maintained in cell culture in the Laboratory of Diagnosis of Parasitism of the Animals, School of Veterinary Medicine of the Federal University of Bahia, Brazil. Of the total samples, it was obtained a prevalence of 50.74 percent. The titles ranged from 1:200 to 1:6400, distributed as follows: 108 (26.21 percent) serum samples showed title of 1:200; 132 (32.04 percent) 1:400; 94 (22.81 percent) 1:800; 46 (11.16 percent) of 1:1600; 23 (5.58 percent) of 1:3200 and nine (2.18 percent) with titers of 1:6400. Among the microrregiões the Itapecuru-Mirim showed the lowest percentage of animals seropositive (20.69 percent) and President Dutra the largest (47.66 percent). It was observed higher prevalence of seropositives in females (46.80 percent) than in males (52.46 percent). There was no significant difference (P> 0.05) for the microrregions variables, sex and age. Concluded that the dairy cattle of the regions studied are exposed to infection by N. caninum.(AU)

Assuntos

RESUMO

Objetivou-se, no presente estudo, pesquisar a prevalência de anticorpos anti-Neospora caninum em 812 amostras de soros sangüíneos de bovinos leiteiros procedentes de propriedades rurais de sete municípios das microrregiões de Itapecuru-Mirim, Médio Mearim e Presidente Dutra, estado do Maranhão, Brasil. Para o cálculo do tamanho da amostra, considerou-se um soroprevalência de 34,7 por cento para N. caninum, com erro máximo de 9,5 por cento e intervalo de confiança de 95 por cento. Para a detecção da presença de anticorpos da classe IgG, utilizou-se a técnica de Imunofluorescência Indireta (IFI), com ponto de corte 1:200, usando como antígeno, taquizoítos da cepa NC-1, mantida em cultura celular no Laboratório de Diagnóstico das Parasitoses dos Animais da Escola de Medicina Veterinária da UFBA. Do total de amostras analisadas, encontrou-se uma prevalência de 50,74 por cento. Os títulos variaram de 1:200 a 1:6400, assim distribuídos: 108 (26,21 por cento) amostras de soro apresentaram título de 1:200; 132 (32,04 por cento) 1:400; 94 (22,81 por cento) 1:800; 46 (11,16 por cento) 1:1600; 23 (5,58 por cento) 1:3200 e nove (2,18 por cento) com títulos de 1:6400. Dentre as microrregiões, a Itapecuru-Mirim apresentou o menor percentual de animais soropositivos (20,69 por cento) e Presidente Dutra o maior (47,66 por cento). Com relação à variável sexo, observou-se maior prevalência de sororreagentes nas fêmeas (46,80 por cento) do que nos machos (52,46 por cento). Não se verificou diferença significativa (P>0,05) para as variáveis microrregiões, sexo e idade. Conclui-se que os bovinos leiteiros das regiões estudadas estão expostos à infecção por N. caninum.

The objective in the present study was to research the prevalence of anti-Neospora caninum in 812 samples of blood serum of dairy cattle from farms of seven municipalities of microrregions of Itapecuru-Mirim, Middle Mearim and President Dutra, state of Maranhão, Brazil. For the calculation of sample size, it was considered a seroprevalence of 34.7 percent for N. caninum, with a maximum error of 9.5 percent and a confidence interval of 95 percent. To detect antibodies, it was used the technique of Indirect Immunofluorescence (IFI), with the cut-off of 1:200, using as antigen, tachyzoites strain NC-1, maintained in cell culture in the Laboratory of Diagnosis of Parasitism of the Animals, School of Veterinary Medicine of the Federal University of Bahia, Brazil. Of the total samples, it was obtained a prevalence of 50.74 percent. The titles ranged from 1:200 to 1:6400, distributed as follows: 108 (26.21 percent) serum samples showed title of 1:200; 132 (32.04 percent) 1:400; 94 (22.81 percent) 1:800; 46 (11.16 percent) of 1:1600; 23 (5.58 percent) of 1:3200 and nine (2.18 percent) with titers of 1:6400. Among the microrregiões the Itapecuru-Mirim showed the lowest percentage of animals seropositive (20.69 percent) and President Dutra the largest (47.66 percent). It was observed higher prevalence of seropositives in females (46.80 percent) than in males (52.46 percent). There was no significant difference (P> 0.05) for the microrregions variables, sex and age. Concluded that the dairy cattle of the regions studied are exposed to infection by N. caninum.

Assuntos