A relatively new A virus subtype that occurs mainly in birds, is highly contagious among them, and can be deadly to them, is the Influenza A (H5N1) virus. Also known as “H5N1 virus”, it has already caused an outbreak in eight Asian countries during the late 2003 and early 2004. Another outbreak was reported in June 2004, still in
About 200 cases of human infection by influenza A (H5N1) virus were reported in almost 13 Asian countries. Usually, this virus does not infect people. Most of the reported cases of human infection have occurred from direct and close contact with infected poultry or contaminated surfaces. Out of these cases of influenza A (H5N1) virus, some occurred to have been transmitted from human-to-human.