The challenge of avian influenza to the veterinary community

Abstract

Avian influenza (AI) is a listed disease of the World Organisation for Animal Health (OIE) that has become a disease of great importance both for animal and human health. The increased relevance of AI in the fields of animal and human health has highlighted the lack of scientific information on several aspects of the disease, which has hampered the adequate management of some of the recent crises. Millions of animals have died, and there is growing concern over the loss of human lives and over the management of the pandemic potential.The present paper aims to identify areas of knowledge of veterinary competence that need to be improved in order to generate information to support the global AI crisis, and highlights the major changes in AI legislation, including regulations related to trade. It also reviews the human health implications of AI, including the mechanisms by which a human pandemic virus may be generated, and the food safety issues related to this infection. The application of control policies, ranging from stamping out to emergency and prophylactic vaccination, are discussed on the basis of data generated in recent outbreaks, and in the light of new regulations, also in view of the maintenance of good animal welfare.Poultry veterinarians working for the industry or for the public sector represent the first line of defence against the pandemic threat and for the prevention and control of this infection in poultry and in wild birds. However, given the current situation, it is imperative that close collaboration is sought and achieved by health officials involved in the veterinary, agricultural and medical aspects of the disease. Only through the exchange of data, experiences, views and information will it be possible to combat this zoonosis, which represents a major threat to public health and animal well-being.

PA-X is a virulence factor in avian H9N2 influenza virus

“…H9N2 influenza viruses have been circulating worldwide in poultry, resulting in severe economic losses due to reduced egg production or increased mortality associated with coinfection with secondary pathogens (Banks et al, 2000;Bano et al, 2003;Capua & Alexander, 2006). H9N2 influenza viruses have been widely reported to infect mammals, including pigs and humans (Abolnik et al, 2010;Butt et al, 2010;Cong et al, 2007;Sun et al, 2010;Xu et al, 2007); there is evidence that a large number of people have been infected with H9N2 viruses, in particular poultry workers (Coman et al, 2013;Jia et al, 2009;Wang et al, 2009).…”

Evaluation of a positive marker of avian influenza vaccination in ducks for use in H5N1 surveillance

“…Although several DIVA strategies based on the specificity of antibody responses have been devised, they have serious limitations, especially for testing duck species in countries like China, Vietnam and Indonesia [8] and [9]. Ducks in these countries are currently being vaccinated with reverse genetics-derived killed H5N1 vaccines that are relatively cheap and have shown good potency against field viruses.…”

Alterations in Hemagglutinin Receptor-Binding Specificity Accompany the Emergence of Highly Pathogenic Avian Influenza Viruses

“…Thus, it is well documented that a switch in the receptor specificity of the avian precursor is essential for the emergence of new stable virus lineages in pigs and humans (24,25,26,27). AIVs of domestic birds also originate from the natural reservoir in aquatic birds (28,29,30). Earlier, it was generally assumed for a long time that all avian viruses have similar receptor-binding specificities and, therefore, that there is no receptor-mediated restriction on interspecies transmission among different bird species (31,32).…”