A 'novel' infectious bronchitis strain infecting broiler chickens in Italy.

An outbreak of severe respiratory disease in flocks of broiler chickens was associated with the isolation of a 'novel' strain of infectious bronchitis virus (IBV). The isolate, designated 624/I, was isolated from 9 of the 11 flocks sampled. The results of cross neutralisation and haemagglutination-inhibition tests showed isolate 624/I to be antigenically distinct from several European and American strains. In a serological survey carried out on affected flocks, specific antibodies to IBV strain 624/I and turkey rhinotracheitis (TRT) virus were detected.