الفهرس 
IntroductionOnly 14 pages are availabe for public view
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Abstract
Behera province, as many provinces in Egypt, has been facing the problem of Spreading of small rural backyard poultry flocks with capacity ranging from the number of 500 to 10,000 birds (Sector 3: Small-Scale Commercial Production System and Sector 4: The Village or Backyard System (FAO 2007) beside the problem of continuous live birds markets persistence which due to inadequate governmental control on these sectors of production and commerce and also may be due to high rises in poultry prices after emerging of AI in Egypt that made small farming practices looks profitable to villagers, so this study was carried through the period from January 2010 to December 2011 on different districts of Behera province. A total of 300 cloacae fecal samples were taken from poultry (broilers, layers, local live chicken markets and free ranging village chickens) at during January 2010 till December 2011. Chickens were sampled opportunistically from various sources in Behera province
Also, data were collected using structured questionnaires including household information, poultry species, flock size and composition, poultry management system, type of housing and feeding, sources of feed and water, extent to which housing is shared with other species, and main sources of poultry. The questionnaires also captured poultry disease prevention measures, poultry disease prevalence and causes, poultry vaccination programs and their effectiveness, general poultry disease management and strategies for sustainable disease control, and extension service delivery. The current study was conducted to monitoring AI using commercially available rapid antigen detection test procedures in small-scale commercial poultry farms (sector3), free ranging village poultry and live birds markets in selected districts of Behera governorate and to investigate biosecurity practices in the examined small-scale commercial poultry farms (sector3) using a specially designed questionnaire directed to farms owners. In addition, determination of some epidemiological parameters including relative risk (RR), attributable risk (AR), odds ratio (OR) and omega measure was done. Lastly, application of the obtained results from epidemiological studies in prevention and control of AI in Behera Province as a model of the Egyptian Provinces as a wholeresearch works on the structure and molecular biology of AIV
during the last years . Such knowledge is crucial to understand the
antigenic variability ,pathogenic molecular base and the mechanisms
involved in the ability to infect and cause disease in several species,
including human .All these aspects are essential for developing safe
and more effective vaccines.(Noda, 2006).
The virus is transmitted by direct contact between infected and
susceptible birds or indirect contact through aerosol droplets or exposure
to virus contaminated fomites (Easterday et al., 1997Infection of domestic poultry by avian influenza (AI) viruses
typically produces syndromes ranging from asymptomatic infection to
respiratory disease and DROP in egg production to severe, systemic
disease nearly with 100% mortality (Swayne and Halvorson, 2003;
Allwright et a1., 1993; Panigrahy et al., 1995; Swayne et al., 1996 and
Jorgensen et al., 1998).The severity of gross lesions has been extremely variable,
depending greatly on the host species, pathogenicity of the infecting
virus, and presence of secondary pathogens. ( Brugh and Beard, 1986;
Capua, et al., 2000; Clavijo, et al., 2001 and Swayne and Beck,
2005).they exhibit diversity in morbidity and mortality . Therefore, as a
preventive strategy against endemic as well as pandemic influenza, it is
important to reduce the spread of H5N1 influenza A viruses in duck
populations (Kim et al., 2008 ).
Avian influenza viruses are generally non pathogenic in wild birds
but sometimes cause significant morbidity and mortality upon
transmission to other species, including domestic birds and mammals
(Murphy and Webster, 1996 and Webster et al., 1992).Waterfowl represent the natural reservoir of all subtypes of
influenza A viruses , including H5N1 . Ducks are especially considered
major contributors to the spread of H5N1 influenza A viruses because