ABSTRACT
Background: Infectious bronchitis (IB) is an acute and highly contagious avian disease, of major economic importance spread worldwide. In Brazil the infectious bronchitis virus (IBV) is widely disseminated in the poultry producing regions, causing economic losses in Brazilian poultry flocks. Case Report: Breeders from Pernambuco, Brazil, from 25 to 58 weeks old had decrease in eggshell quality (deformation and thin bark). Necropsy was performed and fragments of trachea, proventriculus, lungs and tonsil were collected for histopathology and Reverse Transcription-Polymerase Chain Reaction (RT-PCR) and cloacal swab also for PCR. Blood was collected for Enzyme Linked Immuno Sorbent Assay (ELISA) for infectious bronchitis. Results: Necropsy examination revealed no noteworthy change, though the RT-PCR was positive to infectious bronchitis variant BR (in all types of sample) and the immune response geometric mean titers (GMT) was 5846 at 25 weeks and 6040 at 47 weeks for infectious bronchitis. Histopathologically, moderate multifocal lymphoplasmacytic tracheitis with hydropic degeneration and individual necrosis of epithelial cells, moderate multifocal lymphoplasmacytic proventriculitis, moderate multifocal lymphocytic bronchitis and diffuse multifocal lymphohistiocytic infiltrate and lymphoid nodule hyperplasia in the tonsil were observed. Conclusions: In view of molecular diagnosis, immune titration and pathological findings, infectious bronchitis can be confirmed in laying hens from Pernambuco, Brazil.