Some studies on Avian Influenza in Egypt ⅠⅠ. Screening on Avian Influenza infection in some chicken flocks

A-Afifi, Manal; S, Yahya; Khir Eldin, A

doi:10.21608/vmjg.2011.368058

Some studies on Avian Influenza in Egypt ⅠⅠ. Screening on Avian Influenza infection in some chicken flocks

Document Type : Original Article

Authors

¹ Dept of Poultry Diseases, Faculty of veterinary Medicine, Cairo University,

² General organisation of Veterinary Services.

³ Dept of Poultry Diseases, Faculty of veterinary Medicine, Cairo University

10.21608/vmjg.2011.368058

Abstract

During the period 2006 to 2009, a total of 1096 blood samples from 92 chicken flocks (21 of breeder flocks,63 of commercial layer flocks and 8 broiler flocks), were collected from different governorates (Giza, Qalubia, Sharkia and Dakahlia) and tested for determination of hemagglutination-inhibition (HI) titers against Avian Influenza (AI). All of the surveyed farms applied blind vaccination programs without serological estimation to MDA and actively acquired humoral immune response to determine timing of priming or boosting(s). HI titer equal to or less than 2⁴ was detected in 76 flocks (82.6%), and there were 16 flocks (17.4%) showed low antibody titer (<4 log2). The results indicated that MDA persisted for 28 days duration after hatchling and these MDA may interfere with early vaccination (less than 2 weeks of age). Early vaccinations within first week of age, with full vaccine dose, were frequently and blindly applied due to panic of AI. The results of evaluation of such flocks at marketing age (30 - 42 days) revealed suboptimal HI titer. For the control of avian influenza, a rapid diagnosis by detecting the causative virus and identifying its subtype is essential. A rapid diagnosis kit for identification of AI by rapid antigen kits (Type A and H5 kit) was used for detection of AIV in three hundred samples, positive samples were 67, (22.33%). Out of 82 samples from Qalubia, positive samples were 18, (21.95%), samples from Giza were 56, positive samples 11 were positive, (19.64%), 13/68 samples from Dakahlia were positive (19.11%) and 25/94 samples from Sharkia were positive (26.59%).

Main Subjects