Persistence of colostral antibodies against Virus-Infection-Associated (VIA) antigen and virus neutralizing antibodies induced by natural infection with foot-and-mouth disease virus in indian buffalo (Bubalus bubalis) calves / Persistência de anticorpos colostrais antiantígeno via ("Virus-Infection - Associated") e anticorpos soroneutralizantes induzidos por infecção natural pelo vírus da febre aftosa em bezerros búfalos indianos (Bubalus bubalis)

ABSTRACT

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.

RESUMO

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.