| Overview |
|
Pandemic influenza is described as a global outbreak, where everyone is susceptible. This type of flu spreads rapidly with an increased risk of death. The 20th century produced three influenza pandemics: 1) the Spanish Flu in 1918-1919, which caused approximately 20-40 million deaths worldwide (500,000 in U.S.); 2) the Asian Flu 1957-1958, which resulted in 1-2 million deaths worldwide (70,000 in U.S); and 3) the Hong Kong Flu in 1968-1969, which caused 750,000 deaths worldwide (34,000 in U.S.).
A more recent outbreak of the swine influenza (H1N1) has sparked concern about an influenza pandemic. Information regarding this outbreak is fluid and the most accurate and up-to-date information can be found at Centers for Disease Control website www.cdc.gov/swineflu/ or WHO website at http://www.who.int/csr/disease/swineflu/en/index.html
An influenza pandemic requires the following: 1) a new human influenza A subtype; 2) which causes serious illness; and 3) spreads easily from human-to-human. The recent outbreak of avian influenza (H5N1) in many parts of the world renewed the possibility of a potential influenza pandemic for the 21st century. Currently, H5N1 does not meet the necessary criteria. It does not spread easily from human to human. However, each new infection increases the possibility of mutation and a chance for wide-spread infection to occur. |