RESUMO
Antibody against virus-infection-associated (VIA) antigen and neutralizing serum antibody to foot-and-mouth disease virus were studied in 32 non vaccinated Indian buffalo calves. Antibody levels against VIA antigen were detected by double immunodifusion in 76.5% of the animals at 3 + ½, 30% at 4 + ½ and 6.2% at 5 + ½ months of age. Antibody against VIA antigen was no longer detectable at 7 + ½, 8 + ½ and 9 + ½ months of age. Neutralizing serum antibody levels were studied in 12 of 32 animals. At 3 = ½ months of age neutralizing serum antibody for O1, A24, and C3 virus were found respectively in 83.3%m 83.3% ans 65.6% of samples. At 5 + ½ months of age neutralizing serum antibody was present against the three types only in 20% of the animals and was not detected at 7 + ½ months of age. Twenty one days after the outbreak in cattle when the buffalo calves were 12 + ½ months old antibody against VIA antigen was again detected in 20 of 32 (62.5%) of the animals. Neutralizing serum antibody was found in up to 63.3% of the animals against type A and 16.6% against type O1 and C3.
Anticorpos anti-antigeno VIA e anticorpos soroneutralizantes foram estudados em 32 bezerros búfalos indianos não vacinados, a partir de 3 + ½ meses de idade até 1 ano. Esses anticorpos foram detectados até os 5 = ½ meses de idade dos animais, até sofrerem infecção natural do vírus da febre aftosa, o que ocorreu aos 12 + ½ meses de idade. O significados destes achados em relação a susceptibilidade dos bubalinos a essa doença é discutido.
RESUMO
Antibody against virus-infection-associated (VIA) antigen and neutralizing serum antibody to foot-and-mouth disease virus were studied in 32 non vaccinated Indian buffalo calves. Antibody levels against VIA antigen were detected by double immunodifusion in 76.5% of the animals at 3 + ½, 30% at 4 + ½ and 6.2% at 5 + ½ months of age. Antibody against VIA antigen was no longer detectable at 7 + ½, 8 + ½ and 9 + ½ months of age. Neutralizing serum antibody levels were studied in 12 of 32 animals. At 3 = ½ months of age neutralizing serum antibody for O1, A24, and C3 virus were found respectively in 83.3%m 83.3% ans 65.6% of samples. At 5 + ½ months of age neutralizing serum antibody was present against the three types only in 20% of the animals and was not detected at 7 + ½ months of age. Twenty one days after the outbreak in cattle when the buffalo calves were 12 + ½ months old antibody against VIA antigen was again detected in 20 of 32 (62.5%) of the animals. Neutralizing serum antibody was found in up to 63.3% of the animals against type A and 16.6% against type O1 and C3.
Anticorpos anti-antigeno VIA e anticorpos soroneutralizantes foram estudados em 32 bezerros búfalos indianos não vacinados, a partir de 3 + ½ meses de idade até 1 ano. Esses anticorpos foram detectados até os 5 = ½ meses de idade dos animais, até sofrerem infecção natural do vírus da febre aftosa, o que ocorreu aos 12 + ½ meses de idade. O significados destes achados em relação a susceptibilidade dos bubalinos a essa doença é discutido.
RESUMO
The results of experiments to investigate antibody to virus-infection-associated (VIA) antigen in 157 sera samples from Indian buffalos (Bubalus bubalis), 370 sera from sheep and 180 sera from goats from some cities of São Paulo State, Brazil, are reported. Antibody against virus-infection-associated (VIA) antigen was found in 52 per cent of Indian buffalos, in 5,4 per cent of sheep and in 11 per cent of goats. These studies were done with sera from animals with well-documented pre-and postexposure histories of foot-and-mouth disease and vaccination.
Foi realizado um estudo sorológico em 157 amostras de soros de búfalos indianos (Bubalus bubalis), em 370 soros de ovinos e em 180 soros de caprinos de algumas propriedades do Estado de São Paulo, Brasil. Os resultados encontrados revelam que 52% dos búfalos, 5,4% dos ovinos e 11% dos caprinos continham anticorpos anti antígeno VIA do vírus da febre aftosa. Esse estudo foi realizado em animais cujo histórico de vacinação e de exposição ao vírus da febre aftosa era conhecido.
RESUMO
The results of experiments to investigate antibody to virus-infection-associated (VIA) antigen in 157 sera samples from Indian buffalos (Bubalus bubalis), 370 sera from sheep and 180 sera from goats from some cities of São Paulo State, Brazil, are reported. Antibody against virus-infection-associated (VIA) antigen was found in 52 per cent of Indian buffalos, in 5,4 per cent of sheep and in 11 per cent of goats. These studies were done with sera from animals with well-documented pre-and postexposure histories of foot-and-mouth disease and vaccination.
Foi realizado um estudo sorológico em 157 amostras de soros de búfalos indianos (Bubalus bubalis), em 370 soros de ovinos e em 180 soros de caprinos de algumas propriedades do Estado de São Paulo, Brasil. Os resultados encontrados revelam que 52% dos búfalos, 5,4% dos ovinos e 11% dos caprinos continham anticorpos anti antígeno VIA do vírus da febre aftosa. Esse estudo foi realizado em animais cujo histórico de vacinação e de exposição ao vírus da febre aftosa era conhecido.