Ecology, Epidemiology and Human Health Implications of Avian Influenza Viruses: Why do We Need to Share Genetic Data?

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. Until recent times, AI was considered a disease of birds with zoonotic implications of limited significance. The emergence and spread of the Asian lineage highly pathogenic AI H5N1 virus has dramatically changed this perspective; not only has it been responsible of the death or culling of millions of birds, but this virus has also been able to infect a variety of non-avian hosts including human beings. The implications of such a panzootic reflect themselves in animal health issues, notably in the reduction of a protein source for developing countries and in the management of the pandemic potential. Retrospective studies have shown that avian progenitors play an important role in the generation of pandemic viruses for humans, and therefore these infections in the avian reservoir should be subjected to control measures aiming at eradication of the Asian H5N1 virus from all sectors rather than just eliminating or reducing the impact of the disease in poultry. Collection and analysis of information in a transparent environment and close collaboration between the medical and veterinary scientific community are crucial to support the global AI crisis.

Evaluation of field and laboratory protocols used to detect avian influenza viruses in wild aquatic birds

“…Ecological studies have established them as a primary source of virus for domestic poultry as well as other animal species including humans (Slemons et al, 1974;Webster et al, 1992). Avian influenza viruses from wild birds usually cause no disease; however, some subtypes (H5 and H7) may undergo mutation and become highly pathogenic, especially in more susceptible domestic species (Capua and Alexander, 2008). All 16 hemagglutinin (HE) and 9 neuraminidase AIV subtypes, and most HE-neuraminidase combinations have been detected in wild birds, predominantly ducks, geese, and shorebirds (Fouchier et al, 2005).…”

“…Thus, there has been increased virus surveillance and establishment of AIV databases, not only in the United States, but around the world. There is a global effort to collect and characterize AIV to identify genetic mutations and antigenic properties (Capua and Alexander, 2008).…”

Bird Migration and Risk for H5N1 Transmission into Qinghai Lake, China

“…Wild aquatic birds are exposed to water that may be contaminated with infected fecal matter, especially at specific sites and during specific seasons when these birds densely congregate at relatively confined and shallow water bodies (Webster et al 1992, Webster andGovorkova 2006). Intensive studies have been performed on the ecology and virology of influenza A viruses as well as on the host ecology, life history, and behavior that can affect virus prevalence in wild bird populations (Alexander 2000, Fouchier et al 2007, Stallknecht and Brown 2007, Weber and Stilianakis 2007, Capua and Alexander 2008.…”

Isolation and characterization of low pathogenic H9N2 avian influenza A viruses from a healthy flock and its comparison to other H9N2 isolates

“…After infection of H9N2 in Chinese children in 1999, these viruses were reported sporadically among humans; however, they were unable to establish widespread infections [7]. Provided that H9N2 viruses have potential to infect humans, monitoring of such cases would be of importance to ascertain their genetic variability and their ability to switch hosts [11].…”