An overview of infectious bronchitis virus in chickens

Abstract

Infectious bronchitis virus (IBV) is one of the foremost causes of economic loss within the poultry industry. IBV is a commonly occurring, economically significant pathogen of commercial chicken. Economic consequences to the poultry industry comprise mortality, growth retardation and high condemnation rates in meat-type birds. In addition, decreased egg production, reduced internal and external egg quality, and reduced hatchability have been documented in layers and breeders affecting the performance of both meat-type and egg-laying birds. Apart from this some nephro-pathogenic strains cause kidney damage. Secondary pathogens can complicate the disease resulting in increased morbidity and mortality. Being a single stranded RNA virus, IBV has an enormous capacity to change both by spontaneous mutation and by genetic recombination resulting into the emergence of new variants. Since the first isolation of virus in 1937, it has been found almost all over the world. In addition, most countries are now known to have their own indigenous IBV variants. Despite the use of currently available live and inactivated vaccines, one of the most important difficulties to control IB is related to emergence of variant strains. The following paper reviews the current status of research into IBV.