MOLECULAR DETECTION OF NEWCASTLE DISEASE VIRUS FROM OUTBREAK CASES IN COMMERCIAL POULTRY FARMS IN NEKEMTE TOWN AND SELECTED DISTRICTS OF EAST WALLAGA ZONE, OROMIA REGION, ETHIOPIA

ADVISOR: LAMA YIMER (DVM, MVSc, ASS. PROFESOR) Newcastle disease (ND) is a highly contagious and economically devastating viral disease affecting poultry worldwide, including Ethiopia. This study aimed to molecularly detect Newcastle disease virus (NDV) responsible for outbreaks in commercial poultry farms in Nekemte town and selected districts of East Wallaga zone, Oromia region, Ethiopia. A cross-sectional study was conducted from December 2024 to May 2025, focusing on farms reporting suspected ND outbreaks. A total of 20 pooled samples (4 pooled oropharyngeal swabs, 4 pooled cloacal swabs and 12 pooled tissue samples) were collected from clinically affected and freshly dead poultry. Real-time reverse transcriptase polymerase chain reaction (rRT-PCR) was employed to detect the NDV M gene. Results confirmed the presence of NDV in commercial poultry farms in Nekemte town and selected districts of East Wallaga zone, with an overall detection rate of 5%. The highest detection was observed in brain tissue samples (33.33%), suggesting viral tropism for neural tissues. The outbreak investigation revealed significant morbidity (15.18%), mortality (7.85%), and case fatality (51.72%) rates, underscoring NDV as a major cause of poultry losses in the areas. Affected poultry exhibited respiratory, gastrointestinal, and neurological symptoms, while postmortem examinations identified hemorrhagic ulcers and liver necrosis, consistent with velogenic NDV strains. Nekemte town (07) had the highest NDV detection rate (25%), while no positives were detected in other study sites, indicating localized outbreaks. The study confirms NDV as a significant threat to poultry farms in the study areas, highlighting the need for improved vaccination programs, biosecurity measures, and further research to characterize circulating strains.<br> Keywords: Detection, East Wallaga zone, Ethiopia, Molecular, Newcastle disease, Outbreak.