The frequency of group A bovine rotavirus (gpA BRV) in calves from 1998 to 2002 was determined by the polyacrylamide gel electrophoresis technique in 2177 faecal samples, of which 1898 samples were diarrhoeic and 279 were of normal consistency (control group) that were collected from asymptomatic calves for comparative purposes. The animals were from beef and dairy cattle herds (n = 321) from 158 counties in seven States (Paraná, São Paulo, Minas Gerais, Mato Grosso do Sul, Mato Grosso, Goiás and Rondônia) and four Brazilian geographical regions (south, south-east, centre-west, and north). GpA BRV was detected in 19.4% (369/1898; p = 0.0001) of the samples collected in calves with diarrhoea and in only 2.2% (6/279; p = 0.0001) of the faeces with normal consistency. The proportion of positive samples collected from beef and dairy cattle herds was 22.8% (205/899; p = 0.0001) and 16.4% (169/999; p = 0.0005), respectively. In relation to age, a higher prevalence of infections was found in calves up to 30 days old, where 33.0% (189/573; p = 0.0001) and 20.2% (138/683; p = 0.0001) of the diarrhoeic faecal samples from beef and dairy cattle herds, respectively, were positive for gpA BRV. These results show the possible importance of inclusion of gpA BRV in the management of neonatal calf diarrhoea in Brazilian cattle herds.

No abstract

No abstract

A detecção de anticorpos anti-Herpesvírus Bovino tipo 1 (BHV-1) foi realizada, através da técnica de soroneutralização, em 1235 amostras de soro de bovinos adultos, não-vacinados contra Rinotraqueíte Infecciosa Bovina. As amostras de soro analisadas foram colhidas em 81 rebanhos, com histórico de problemas reprodutivos, incluindo animais com aptidão para carne e leite, provenientes de 30 municípios do Estado do Paraná. Na amostragem proveniente de rebanhos leiteiros, 41,9% (409/977) das amostras de soro e 90,5% (57/63) dos rebanhos foram considerados positivos. Em bovinos de corte, o índice de soropositividade foi de 50,8% (131/258) e 100% (18/18) para amostras de soro e rebanhos, respectivamente. As freqüências de 43,7% (540/1235) de animais e 92,6% (75/81) de rebanhos soropositivos demonstram que as infecções por BHV-1 apresentam-se amplamente disseminadas nas regiões estudadas.

A total of 71 group A rotavirus field strains, detected by polyacrylamide gel electrophoresis and enzyme immune assay, were submitted to genotyping by a multiplex nested-reverse transcription-polymerase chain reaction (RT-PCR). Faecal samples were obtained from calves with diarrhoea, between January 2000 and December 2001, from 14 dairy and beef cattle herds located in Mato Grosso do Sul, Sa˜o Paulo and Parana´States, Brazil. Thirty-five rotavirus field strains were detected in faeces from calves born to vaccinated dams with inactivated commercial vaccine containing the rotavirus strain P[1],G6 from seven herds while 36 rotavirus field strains were obtained from diarrhoeic calves from other seven herds without rotavirus vaccination. Identification of P and G rotavirus genotypes was possible in 94.3% (67/71) of the strains. However, G genotype could not be identified in two strains, P genotype in another strain and both genotypes were not detected in a third strain. P and G rotavirus genotype associations were identified in rotavirus field strains from non-vaccinated and vaccinated herds at similar rates of 94.4% (34/36) and 94.3% (33/35), respectively. In non-vaccinated herds binary combinations were P[1],G6 (three herds; 12 strains), P[1],G8 (three herds; six strains), P[5],G6 (two herds; 10 strains) and P[11],G8 (one herd; four strains). The genotype P[11],G6 was the most frequent (three herds; 12 strains) in vaccinated herds, followed by P[5],G6 (two herds; three strains), and P[11],G8 (two herds; eight strains). Mixed infections were observed in one non-vaccinated herd (two strains) and in four vaccinated herds (10 strains). Identification of binary combinations was not possible in one strain from nonvaccinated herds and two strains from vaccinated herds. Unusual genotypes were more frequent (91.4%) in nonvaccinated herds than those from prototypes of bovine rotavirus strains. Nebraska calf diarrhoea virus (NCDV)-like genotype was found in none of the rotavirus field strains detected in diarrhoeic calves born of vaccinated dams.