Infectivity of Infectious Bursal Disease Virus for Embryonating Eggs

THE disease that Cosgrove (1962) reported as avian nephrosis has since been referred to as infectious bursal disease. Early attempts to propagate the infectious bursal disease virus (IBDV) by serial passage in embryonating eggs frequently resulted in failure to maintain the virus. Landgraf et al. (1967) reported a typical experience that has been observed by other workers. Infective tissue suspensions killed all inoculated embryos on first passage. Materials from embryos of the first passage killed 30% of those inoculated on the second passage, and on the third passage there was no embryo mortality. In some of the initial studies with IBDV it was observed that eggs from certain supply flocks would not support the growth of the virus, suggesting that parental antibodies from immune dams may have inhibited the virus. However, this did not provide the full explanation for failures to maintain the virus since serial passage failed even when. . .