Serological Study of Australian Chickens Affected with a Uremia Disease Syndrome

Abstract

Serums were assayed for infectious bronchitis (IB) antibodies and were obtained from convalescent Australian chickens affected with a uremia disease syndrome similar to a disease observed in the United States. Without exception, all flocks that demonstrated clinical signs of the disease showed significant neutralization indices (NT''s). However, it was found that inapparent, as well as apparent, infectious bronchitis virus (IBV) infection also occurred. Eight of 13 flocks tested in the Sydney area had significant antibody levels against Massachusetts, Connecticut, Iowa 97, Iowa 609, Gray, and Holte IBV types. Serums from Armidale and Tweed Heads area flocks also demonstrated a broad antibody response to IBV infection under field conditions. Three different Australian isolates used in laboratory trials proved capable of stimulating significant neutralizing antibody levels to all 6 of the IB virus types found in the United States. Two of these proved capable of causing death losses of 16 to 20%. To date, the wide spectrum of antigenic activity found in this study has not been demonstrated with IB virus isolates in the United States, but some crossing-over has been noted. In reciprocal neutralization tests, Australian virus isolates causing uremia disease in the Armidale area were not neutralized by Gray, Holte, Connecticut, Massachusetts, Iowa 97, and Iowa 609 antiserums. No distinct or clear-cut relationship could be established with the isolates from the United States that cause a similar uremia disease syndrome. The possible relationship of uremia disease, and the nephritis-nephrosis syndrome to so-called blue comb or avian monocytosis and IB virus infection was discussed.