Avian Influenza Virus
Daniel R. Perez, Silvia Carnaccini, Stivalis Cardenas-Garcia, Lucas M. Ferreri, Jefferson Santos and Daniela S. Rajao
from: Avian Virology: Current Research and Future Trends (Edited by: Siba K. Samal). Caister Academic Press, U.K. (2019) Pages: 1-42.
Influenza is one of the most devasting respiratory diseases of poultry. Avian influenza (AI) is a viral disease caused by influenza A viruses (IAVs) that affects the respiratory, digestive, and nervous systems of several bird species, including domestic poultry and wild aquatic birds. The World Organization for Animal Health (OIE) has included highly pathogenic avian influenza (HPAI) as a List A notifiable disease. The past couple of decades have seen a sharp increase in the number of AI outbreaks, which have led to devastating economic losses in the poultry industry as a direct result of infection, as well as trade limitations and public opinion repercussions. AI also has public health implications, in particular zoonotic strains that have emerged in southeast Asia with the ability to cause lethal infections in humans and, therefore, are of great pandemic concern. Over the past two decades, particularly with the development of reverse genetics systems for influenza viruses, we have learned a great about the mechanisms involved in pathogenesis and transmission of avian-origin influenza viruses in birds and humans. Avian influenza surveillance efforts around the world have provided the discovery of novel hotspots of influenza activity in wild birds as well as novel influenza A viruses in fruit bats and have greatly improved our understanding of the ecology and the evolution of these viruses. Novel and upcoming sequencing technologies are allowing pen-side diagnostics and rapid phylogenetic characterization of influenza viruses from a variety of sources and animal species. Improvements in vaccine technologies and vaccination regimens are paving the way for more efficient control of AI in poultry. Yet, many challenges remain. It is the objective of this chapter to provide an overview of what is known about AI and its implications for animal and human health read more ...