Avian Herpesviruses

Avian herpesviruses (AHV) are an important group of pathogens affecting a most species of domestic, wild and captive birds. With a large DNA genome that shows some degree of structural conservation, AHV encode a number of structural and non-structural proteins that are usually expressed in different kinetic classes. While a number of the AHV are highly pathogenic producing severe diseases in chickens and other poultry species, there are many others where only limited information is available on the pathobiological features. Pathogenesis of AHV can differ based on the tissue tropism and the nature of the diseases they cause in different species, ranging from respiratory diseases to lymphomas. However, as in the case of well-studied mammalian herpesviruses, one major hallmark of AHV is their ability to establish latent infection in different cell types in the infected hosts. With the advances in sequencing and PCR-based technologies, increasing amounts of data are available on the phylogenetic relationships of AHV, which are also proving to be valuable in disease diagnosis. Strategies for the prevention and control of AHV infections vary depending on the epidemiology and pathogenesis of the specific diseases. However, basic principles include coordinated efforts of rapid diagnosis, improved biosecurity and vaccination.