Newcastle disease (ND) is a serious infectious disease of bird species triggered by Avian
Orthoavula virus 1 (AOAvV-1) which was previously called ND virus and it infects more
than 200 poultry types. The disease is highly devastating in susceptible bird species. In
Egypt, despite the application of colossal vaccinations for controlling ND since several
decades, the illness remains one of the most destructive diseases that impacts enormous
chicken farms. Continuous mutations of NDV have led to twenty genotypes, and genetic
variation could cause disease epidemics in previously immunized birds. Recently, NDV
genotype VII (NDV GVII) become the source of the current epidemics all over the world
including Egypt. One of the most critical features for NDV control is a thorough
understanding of the pathophysiology of NDV particularly genotype VII in various poultry
species. This review sheds light on some important aspects of the epidemiology and
pathogenesis of NDV in general and NDV GVII especially.