The classification of new serotypes of infectious bronchitis virus isolated from poultry flocks in Britain between 1981 and 1983.

Between 1981 and 1983 10 isolations of infectious bronchitis (IB) virus were made from broiler chickens with respiratory infection and five from breeder chickens showing aberrant egg production. One isolate was serologically similar to an IB virus isolated in England in 1976; the remainder were related to three of the four serotypes of IB virus first isolated in The Netherlands (Davelaar et al., 1981). Neutralising antibody to each of the four Dutch serotypes of IB virus was widespread in the sera of commercial chickens in England, Wales and Scotland. Their possible role as causal agents of disease in the flocks from which they were isolated is discussed.