Authors : A. Ballal , A.E. Karrar and A.M. ElHussein
Abstract: Outbreaks of suspected IB disease occurring in a number of commercial layer flocks at Khartoum and El Gazira states were studied during years (2000- 2001). Affected birds were of different breeds (Lohmann, Bovans Hisex). Their ages were from 5 / –7 months. The main clinical signs varied from mild respiratory signs to diarrhea sometimes yellowish in colour. Drop in egg production (up to 60%) was recorded in some flocks. IB virus was isolated from these outbreaks. Using virus neutralization (VN) and haemagglutination inhibition (HI) tests, three of these IB field isolates (M114/2000, K170/2000 and K158/2001) were antigenically similar to IB virus strain 4/91 (Neutralization index 4.4 to 4.8 and VN titer > 11(log ) were recorded). Isolate (K110/2000) on the other hand, was antigenically similar to IB virus Mass. (M41) strain (HI titer >11 log was recorded). This 2 is the first time to identify IB virus strain antigenically similar to IB virus strain 4/91 in Sudan.
A. Ballal , A.E. Karrar and A.M. ElHussein , 2005. Isolation and Characterization of Infectious Bronchitis Virus Strain 4/91 from Commercial Layer Chickens in the Sudan . Journal of Animal and Veterinary Advances, 4: 910-912.