[01] Wegdan H. A., Veterinary Research Institute (VRI), Khartoum, Sudan. [02] Khair S. A. M., Veterinary Research Institute (VRI), Khartoum, Sudan. [03] Zakia A. M., Veterinary Research Institute (VRI), Khartoum, Sudan.

During the epidemic of highly pathogenic avian influenza (HPAI) virus in 2006 several outbreaks of severe fatal diseases with 100% mortality and morbidity occurred in some poultry farms in Khartoum and Elgazera States, Sudan. The present study deals with the molecular and histopathological evaluation of these outbreaks. The most striking gross and histopathological changes were vasculitis, severe generalized systemic haemorrhages, and congestion. Mild to severe diffuse inflammatory reaction and necrosis were detected in brain, visceral organs and subcutaneous tissue of skin of combs and wattles. Virological results indicate that allantoic fluids of the inoculated samples were positive for type A avian influenza. Allantoic fluids sent to OIE, FAO (the National Reference Laboratory for Newcastle Disease and Avian Influenza, Padova, Italy) for confirmation. The isolates were analysed using reverse transcriptase-polymerase chain reaction (RT-PCR), real-time PCR, and the amino acid sequence of the H5 gene is positive to highly pathogenic AI subtype H5N1. In conclusion: The results obtained confirmed the presence of highly pathogenic AI virus subtype H5N1 in Sudan

Avian Influenza, H5N1 Molecular, Histopathology, Domestic Fowl, Sudan

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