... Finally, throughout the debate on the respective roles of migratory and domestic birds in
the dispersal of H5N1, there are numerous statements that are not based on data
presented, or when they are based on data, are not necessarily conclusive. Two such
examples are detailed below. First, it has been concluded that wild birds are not an
important carrier because HPAI viruses such as H5N1 are rarely isolated from apparently
healthy wild birds [10]. However, the same statement can be made about domestic
chickens in areas where H5N1 is considered endemic [5]. Thus, the same logic, as
applied to migratory birds, could be used to conclude that domestic poultry are not an
important carrier. In a second example, it has been speculated that wild birds could not
effectively transport H5N1 over long distances as migratory performance would be negatively
influenced by the infection [4]. While others pointed out that H5N1 appeared
to kill wild birds nearly as efficiently as domestic poultry and noted that ?dead ducks
don?t fly? [1]. However, many of the same arguments would likely apply to long
distance transport of domestic poultry. During transport, domestic birds are frequently
deprived of food and water for extended periods and are exposed to extreme
environmental conditions. Again, the same logic could be used to conclude that exposed
domestic poultry are less likely to survive long distance transport for the same
immunological reasons. In both of these examples, while the original statements may be
strictly true, the conclusions drawn from them are not necessarily valid or informative. ...
