Assessment of an Infectious Bursal Disease outbreak in broilers in Western Romania

This study was conducted on a broiler farm in Western Romania between 2023 and 2024, to investigate an outbreak of Infectious Bursal Disease (IBD) in chickens. The study involved four poultry houses where broiler chickens were raised on permanent bedding. Epidemiological, clinical, and anatomopathological monitoring was performed to identify the disease, and molecular biology tests were used to confirm the causative virus strain. IBD outbreaks were suspected based on clinical signs and pathological lesions observed in the affected chickens, with the first symptoms appearing at 21 days of age. Clinical signs included lethargy, reduced feed intake, huddling behaviour, and watery white diarrhea around the cloacal region. The disease evolved in primary outbreaks lasting six days, with the highest mortality peak occurring on day five. The epidemiological investigation highlighted deficiencies in biosecurity measures, such as improper sanitary filters and unrestricted movement of personnel and vehicles within the farm. Pathological examination revealed characteristic lesions, including hypertrophy of the bursa of Fabricius. Molecular biology tests (rPCR) confirmed the presence of highly virulent (vv) and attenuated (att) IBD virus strains. The study emphasizes the importance of biosecurity measures, proper vaccination, and improved farm hygiene to control IBD outbreaks. In conclusion, the outbreak of IBD in this farm was caused by highly virulent viral strains, underscoring the need for stringent biosecurity and technological improvements to prevent the spread of the disease.