Serological investigation of antibodies against respiratory viruses in calves from Brazilian family farming and their relation to clinical signs of bovine respiratory disease

Abstract

Bovine respiratory disease (BRD) is responsible for economic losses in cattle production. Viruses are categorized as primary etiological agents. The aims of this study were to evaluate the presence of antibodies against bovine viral diarrhea virus (BVDV), bovine herpes virus type 1 (BoHV-1), and bovine respiratory syncytial virus (BRSV) in healthy and BRD calves from family farming in relation to clinical signs of BRD. Hundred and forty-five calves were randomly selected and physical examination was performed. Only 123 animals were classified as healthy and BRD calves. Antibodies were evaluated by virus neutralization test. Person’s Chi-square test and Fisher’s exact test were performed as univariate analysis. Binary Logistic Regression was applied as multivariate analysis. Variables with P<0.10 were considered statistically significant. Variables with 0.15<P<0.10 were considered as statistical tendencies. Antibodies against BoHV-1, BVDV, and BRSV were detected in 32%, 23% and 37% animals. Antibodies against both three viruses were detected in 26.8% of calves. The presence of antibodies against BRSV were associated to normal heart rates (P=0.018) and unilateral airflow (P=0.035). Tendency was observed to unilateral airflow (P=0.06) Statistical tendencies were observed to Ab-BoHV-1 and body temperature (P=0.119) and breathing pattern (P=0.123). The profile of antibodies against respiratory viruses in calves from Brazilian family farming was firstly described. The results confirmed the importance of some clinical signs to viral infection.

The Participation of a Malignant Catarrhal Fever Virus and Mycoplasma bovis in the Development of Single and Mixed Infections in Beef and Dairy Cattle With Bovine Respiratory Disease

“…In Brazil, information relative to the occurrence of BRD is limited when compared with studies from North America (25)(26)(27)(28) and Australia (29,30). Previous studies done in Brazil were designed to investigate a single (31)(32)(33)(34)(35)(36)(37) or several agents (2,16,(38)(39)(40)(41)(42)(43) associated with BRD. These studies focused on the molecular identification of agents, with and without the histopathologic diagnosis of the patterns of pulmonary disease.…”

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

“…La infección es más severa en animales jóvenes (Gershwin, 2007). La falta de datos brasileños sobre la circulación de estos virus en los terneros (Gaeta et al 2018) impide la formación de programas de vacunación efectivos y la determinación de las pérdidas económicas. Se planteó este estudio con el objetivo de evaluar la presencia de anticuerpos frente a VDVB, HVBo-1 y VRSB en terneros, con y sin enfermedad respiratoria, criados en de neutralización vírica.…”

“…La frecuencia de anticuerpos contra VDVB fue menor que la detectada en otros estados como Maranhão (Chaves et al, 2010), Rio Grande do Sul (Quincozes et al, 2007, Piovesan et al, 2013 y Goiás (Brito et al, 2010). Sin embargo, se encontraron mayores frecuencias de anticuerpos que los encontrados en un sistema extensivo (Gaeta et al, 2018). La presencia de anticuerpos frente al VRSB fue mayor que la detectada en otros estudios hechos en Brasil.…”

“…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).…”

“…La presencia de anticuerpos contra VDVB se asoció a la presencia de exudado nasal mucopurulenta / purulenta. En un trabajo similar, Gaeta et al (2018) observaron la asociación de la misma manifestación clínica con anticuerpos contra el VRSB. Aunque son virus diferentes, se sabe que la presencia de exudado nasal seroso es característico de infecciones respiratorias de origen viral (Gonçalves, 2014).…”