الفهرس 
REVIEW OF LITERATUREOnly 14 pages are availabe for public view
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Abstract
Data collected from epizootiological investigation of 12 current IBD outbreaks showed that the infectious bursal disease virus (IBDV) affected vaccinated flocks and causes acute IBD .
Field and laboratory observation suggested that the IBD field viruses are in the majority of highly virulent pathotype producing acute disease with severe clinical picture. Detection of IBDV RNA in bursal homogenates by RT/PCR indicated that the nucleotide sequence of a 248 bp of the VP2 gene showed that strains designated as. (IBDV/Menouf/2014,IBDV/Gharabea/2014,IBDV/Alex1/2014,IBDV/Alex2/2014 ,IBDV/cairo/2014) have amino acid sequence identity between each other (95–100%)and between previous reported vvIBDV strains (Giza 2008) strain (96–98%),while isolates (IBDV/Gharabea/2014, IBDV/cairo/2014) have amino acid sequence identity between each other (99%) and with classical strains (IBDV HK 46)(97-98%) and(92%) to vaccine strain.
This study reported the characterization of three vvIBDV and two classical strains from field cases of IBD in Egypt during 2014. The genotyping of Egyptian vvIBDV indicate progressive evolution and some of them were genetically distinct from the previously reported Giza 2008 field strain.
Indeed, the study reports the continuous evolution and persistence of the VVIBDV strains in poultry population.