Are migratory birds carrying the virus from one country to another?
The role of migratory birds in the transfer of the H5N1 strain is not clear. The pattern and timing of several outbreaks of H5N1 in Asia, Africa, and Europe have not coincided with periods of major migratory movements or migratory routes. However, there are also reports of wild bird mortality that are associated with outbreaks of highly pathogenic avian influenza H5N1 in poultry. It is not known if wild birds were the source of the virus or if wild birds acquired the virus from poultry. Once infected, wild birds can be a source of infection for domestic poultry that are kept outside and not physically separated from wild birds.
