Studies on Some Immunological Aspects of Australian Infectious Bronchitis Viruses

Abstract

Prior to 1962, infectious bronchitis (IB) virus had not been identified in Australia. Certainly the disease syndrome caused by IB virus, as seen in Europe and America (Beister and Schwarte, 1959) had not been described in Australia (Gilchrist, 1962, Hungerford, 1962), although reports by Hart (1946), Newton and Simmons (1963) and Gilchrist (1962), all describe syndromes which had some aspects reminiscent of IB infections. One of the prominent poultry diseases at that time had been characterised by a breakdown in kidney function producing a 'uraemia' or nephritis (Hungerford, 1969). This syndrome had been seen since 1948 and was thought possibly to be caused by some nutritional factor (Beilharz and McDonald, 1960). In 1962, Cumming isolated a virus from cases of nephritis and suggested the virus to be IB. This was confirmed by Cumming (1963, 1964), Gilchrist (1963), and Gilchrist and Sinkovic (1964). Supporting serological evidence for the identity of the virus being IB was given by cross neutralisation studies with American IB viruses (Winterfield et al., 1964a), British IB viruses (Berry and Stokes, 1968) and some German IB viruses (von Bulow, 1967). Berry and Stokes (1968) also confirmed the Australian IB virus as a corona-virus by electron microscopy. ... The main approach to the disease problem associated with IB virus infections in the past has been based on the serum neutralisation relationships of the viruses involved and the ability of vaccine viruses to induce these antibodies in birds. The approach to the problem used in this thesis has been based on the ability of virus infections to induce resistance in birds to the affects of virulent IB virus challenge and to evaluate the relationship of this resistance to antibody production. This approach has been aided by, the characteristic of Australian IB viruses to cause death with nephritis under controlled experimental conditions.