Rotavírus bovino: fatores de risco, prevalência e caracterização antigênica de amostras em rebanhos leiteiros no estado de São Paulo

Retrospective study of rotavirus in beef and dairy herds in the State of São Paulo, Brazil

“…Studies performed in other countries indicated large variation in the prevalence rates of rotavirus infection among bovine herds, with prevalence rates of 7-98%, with a mean of 30-40% (Dhama et al, 2009). In Brazil, several authors reported the occurrence of rotavirus infection in bovine herds in the State of São Paulo, with different prevalence rates, some of which were similar to that in the present study (Buzinaro & Freitas, 2002;Jerez et al, 2002;Freitas et al, 2011). The variation among these results may be due differences between the sampled herds, and because most studies on rotavirus in cattle were performed in herds with outbreaks of diarrhea.…”

“…The sampled beef herds had a high prevalence of infection (22.8%), confirming the importance of this virus as an etiological agent of neonatal diarrhea in calves (Alfieri et al, 2006). However, other researchers have found lower prevalence rates in similar studies (Brito, 1994;Freitas et al, 2011). The reproductive management methods used for breeding animals in Brazil, concentrating calving within a short period of time, may facilitate transmission of the virus and increase the prevalence of diarrhea, as previously reported (McNally & Logan, 1983).…”

“…Positive samples were detected in different municipalities, showing that rotavirus plays an important role in the etiology of diarrhea in these localities, which has unfavorable implications for the production of dairy calves. Freitas et al (2011) also detected a higher occurrence of disease in animals with diarrhea in dairy herds.…”

Outbreak of neonatal diarrhea caused by multiple genotypes of rotavirus A in a beef calves herd

“…In Brazil, as in other countries, diarrhea outbreaks caused by RVA continue to be the most common cause of losses of calves less than one month (Freitas et al 2011, Blanchard 2012). The 53.3% (16/30) of the diarrheic fecal samples that were positive for RVA in the present study suggested that this enteric virus was the major etiological agent associated with the neonatal diarrhea outbreak described.…”

“…Among the P genotypes, P[1], P[5] and P [11] are found in RVA strains of bovine origin. The G and P genotype combinations most commonly found in bovine RVA strains are G6P (Alfieri et al 2004, Caruzo et al 2010, Martella et al 2010, Freitas et al 2011, Badaracco et al 2012, Papp et al 2013, Collins et al 2014, Medeiros et al 2014. RVs cause malabsorption and toxin-mediated secretory diarrhea, especially in calves less than 3 weeks old (Foster & Smith 2009).…”