| Abstract: |
In the present study, twelve avian influenza isolates were isolated inlkyonated chicken eggs (ECE) from diseased backyard ducks that accompaniedken flocks suffered previously from sudden onset of nervous signs with highality rates. The collected ducks presented signs of severe depression, anorexia,greenish or watery diarrhea. Ducks displayed severe neurological signsraeterized by tremors, incoordination, seizures, tilted head, torticollis, andlysis. Sinusitis, cloudy eyes, and blindness were also recorded. Ducks showed~h mortality rates. Necropsy findings of the affected ducks revealed picture ofncernia. The most common gross lesions were congestion and hemorrhages ofseles and internal organs such as lungs, heart, liver, pancreas, proventriculus,odenum, and brain. Necrotic foci in liver and pancreas with spleen atrophy and ney nephrosis were also recorded.The viral isolates were identified using hemagglutination inhibition (HI) testng specific reference H5NI antiserum and reference H5NI AIV. All isolatesere identi fied as A IV of subtype H5N I. One-step reverse-transcriptase polymeraseain reaction assay (R T -PCR) was used for detection and subtyping of avianOuenza virus using specific pairs of primes to amplify the hemagglutinin gene of,btype H5 and neuraminidase gene of subtype N I. Analysis of RNA extracted/Om the allantoic fluids of avian influenza virus inoculated chicken embryos bygarose gel electrophoresis yielded positive reactions of correct size as H5 subtype ecific primers (545 base pairs in size) and NI subtype specific primers (616 base ’airs in size).A pathogenicity study in 2-week-old balady ducks was performed. Ducksere divided into 5 groups, 10 each; a control group (negative control) and four roups inoculated intranasally with 0.1 ml of inoculum containing 106 ElDso/ml .
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