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Pandemic Influenza

A pandemic is a global disease outbreak. A flu pandemic occurs when a new influenza virus emerges for which people have little or no immunity, and for which there is no vaccine. The disease spreads from person-to-person, causing serious illness, and can sweep across the country and around the world in a very short time.

It is difficult to predict when the next influenza pandemic will occur or how severe it will be. Wherever and whenever a pandemic starts, everyone around the world is at risk. Through measures such as border closures and travel restrictions, countries might delay arrival of the virus, but cannot stop it.

Bird Flu

Health professionals are concerned that the continued spread of a strain of avian H5N1 virus (also known as bird flu) 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 (able to produce a lot of disease), is spread by migratory birds, can be transmitted from birds to mammals and in some limited circumstances to humans, and, like other influenza viruses, continues to evolve.

Since 2003, a growing number of human H5N1 cases have been reported in Azerbaijan, Cambodia, China, Djibouti, Egypt, Indonesia, Iraq, Lao Democratic People's Republic, Nigeria, Thailand, Turkey, and Vietnam. More than half of the people infected with the H5N1 virus have died. 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.

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