Frequência e fatores associados à infecção pelo vírus da diarreia viral bovina em bovinos leiteiros não vacinados no Estado do Maranhão

Abstract

RESUMOA frequência de anticorpos contra o vírus da diarreia viral bovina (BVDv) foi pesquisada na bacia leiteira do Estado do Maranhão. Amostras de soro sanguíneo de 920 fêmeas bovinas não vacinadas contra a diarreia viral bovina (bovine viral diarrhea, BVD) foram analisadas pelo método de ELISA indireto. O estudo foi realizado em 92 propriedades leiteiras, pertencentes a 23 municípios localizados nas regionais de Açailândia, Bacabal, Ilha de São Luís, Imperatriz e Pedreiras. As amostras de soro foram coletadas de fêmeas com ou sem sinais clínicos de infecção pelo vírus (bovine viral diarrhea virus, BVDv) e estratificadas segundo a faixa etária (> 3 anos, entre 3 a 7 anos e > 7anos). Durante a coleta das amostras, aplicou-se questionário epidemiológico para investigar fatores que poderiam estar associados à infecção. Das 920 amostras de soro analisadas, 65,66% (n = 604) foram reagentes. Nas regionais obtiveram-se frequências de anticorpos de 67,5%, 53,57%, 80%, 63,75% e 74%, para Ilha de São Luís, Imperatriz, Açailândia, Pedreiras e Bacabal, respectivamente. Nos 23 municípios amostrados foram encontrados animais reagentes, com detecção de bovinos sorologicamente positivos em 94,57% das propriedades. Das variáveis consideradas fatores de risco para a infecção pelo BVDv, a presença de suínos, ausência de assistência veterinária, uso de monta natural ou de monta natural associada à inseminação artificial e diarréia, apresentaram significância estatística (P < 0,05) associada à soropositividade para BVDv. Os resultados obtidos demonstram níveis elevados de frequência do BVDv no rebanho bovino de aptidão leiteira do Estado do Maranhão. PALAVRAS-CHAVE: BVD, BVDv, anticorpos, ELISA, bacia leiteira. ABSTRACT FREQUENCY AND FACTORS ASSOCIATED WITH BOVINE VIRAL DIARRHEA VIRUS INFECTION IN NONVACCINATED DAIRY COWS IN THE STATE OF MARANHÃO, BRAZIL.The frequency of antibodies against the bovine viral diarrhea virus (BVDv) was studied in a dairy herd of the state of Maranhão, Brazil. Blood serum samples from 920 cows not vaccinated against bovine viral diarrhea (BVD) were analyzed through the indirect ELISA method. The study was carried out on 92 dairy farms from 23 districts located in the regions of Açailândia, Bacabal, São Luiz Island, Imperatriz, and Pedreiras. The serum samples were collected from cows with or without BVDV infection symptoms and classified according to age (> 3 years, 3-7 years, and > 7 years old). An epidemiological questionnaire was applied during sample collection to elucidate the factors which could be associated with the infection. From the 920 serum samples analyzed, 65.66% (n = 604) were reagent. The antibody frequency obtained was 67.5%, 53.57%, 80%, 63.75%, and 74%, for São Luiz Island, Imperatriz, Açailândia, Pedreiras and Bacabal, respectively. In the 23 districts studied, serologically positive cows were found on 94.57% of the farms. From the variables considered as risk factors for BVDv infection, the presence of swine, lack of veterinary assistance, use of natural breeding or natural breedin...

Epidemiological analysis of infection by the bovine viral diarrhea virus on family farms in Brazil

“…The high number of herds that had at least one reagent animal (100.0%) is similar to the results reported by Fino et al (2013) in the state of Santa Catarina and compatible with the 82.4% found in Rio Grande do Sul (QUINCOZES et al, 2007) and with the 97.6% found in the state of Maranhão (CHAVES et al, 2012). These results could be associated with inadequate procedures of sanitary management on the family farms in question, resulting in the introduction of viremic cattle (acute infection or PI).…”

“…Quincozes et al (2007) observed that the presence of sheep in consortium breeding systems has been considered a risk factor for the presence of anti-BVDV antibodies. Meanwhile, Chaves et al (2012) reported that pig breeding is a statistically significant risk factor for BVDV seropositivity.…”

Risk factors analysis applied to antibodies to Bovine Herpesvirus Type 1, Bovine Viral Diarrhea Virus, Bovine Leukemia Virus and Brucella abortus among cattle: a cross-sectional study

“…Some of these variables were previously described in other studies as important risk factors for infections affecting cattle. Among the aforementioned variables, one finds purchase of animals, presence of sheep/goats and pigs, diarrhea, miscarriage and pasture sharing (BEZERRA et al, 2012;CHAVES et al, 2012;OLIVEIRA et al, 2013;PRAZERES et al, 2014;CARVALHO et al, 2016).…”

Estudio serológico frente a los virus respiratorios en terneros en un sistema semi-intensivo y su relación con la sintomatología respiratoria

“…En las comunidades rurales del Pontal del Paranapanema (São Paulo, Brasil), Gaeta et al (2018) detectaron un 37,4% de terneros con serología positiva. Por último, la frecuencia de anticuerpos contra HVBo-1 fue similar a las encontradas en los estados brasileños de Espírito Santo (Santos et al, 2014) y Maranhão (Chaves et al, 2012) y mayores que la encontrada en los asentamientos en el estado de São Paulo (Gaeta et al, 2018) y en Rio Grande do Sul (Becker et al, 2015). El muestreo, la edad de los animales y las distintas pruebas diagnósticas empleadas pueden estar relacionadas con los diferentes resultados encontrados en otros estudios (Coutinho et al, 2009).…”