Role of Migratory Birds in Spreading Influenza Viruses

Abstract

The major source of several influenza viruses in other species are aquatic birds. Long distances travel is carried out by many migratory bird species between their breeding grounds and non-breeding areas. These migratory birds as well as wild birds are considered as reservoirs of majority of influenza A viruses. The geospatial analysis of the pathways of migratory birds present in different geographical locations will throw further light on their role in influenza virus epidemiology. The influenza virus dynamics among migratory wild birds and mammals including humans are closely linked as is evident from H1N1 spread. It is important to note that the migratory water fowls play a negative role as far as the economic benefit out of poultry industry is concerned and imposes threat to lives of human as well, because of their capability to transmit the highly pathogenic avian influenza (HPAI) virus across the continents. Interestingly, several species of familiar songbirds or perching birds act as bridge species and has a possible role in transmitting the H5N1 AI to or from wild habitat. Surveillance and tracking of migratory and resident wild birds, utilisation of ornithological expertise, and analysis of the H5N1 ecology are needed for increasing our knowledge about strain- or host-specific pathogenecity, degree of shedding of virus and the routes of transmission between wild birds. In this aspect, it is quiet noteworthy that 13 membered International Scientific Task Force including UN bodies, wildlife treaties and specialist intergovernmental as well as non-governmental organizations have been created on the ground of various scientific studies concerning the role of migratory birds as potential transmitter of H5N1 subtype of Highly Pathogenic Avian Influenza (HPAI) virus.