Health professionals are concerned that
the continued spread of a highly pathogenic avian H5N1 virus across
eastern Asia and other countries represents a significant threat to
human health. The H5N1 virus has raised concerns about a potential human
pandemic because: It is especially virulent, that is, very active in
causing injury or marked by rapid, severe and potentially
life-threatening illness. It is being spread by migratory birds. It can
be transmitted from birds to mammals and, in some limited circumstances,
to humans, and like other influenza viruses, it continues to evolve.
Since 2003, a growing number of human H5N1 cases have been reported in
Azerbaijan, Cambodia, China, Djibouti, Egypt, Indonesia, Iraq, Nigeria,
Thailand, Turkey and Vietnam. Most of these cases are all believed to
have been caused by exposure to infected poultry. There has been no
sustained human-to-human transmission of the disease, but the concern is
that H5N1 will evolve into a virus capable of human-to-human
transmission. |
