email: David Zage
An influenza pandemic or world wide epidemic occurs when the influenza virus undergoes antigenic shift. When the virus' protein coat changes the immune system of the host is unable to combat the virus and in turn the virus runs rampant. Pandemics occur every twenty to forty years and wide-spread infection and death usually accompany them. There have been several pandemics this century including the Spanish Flu pandemic which killed twenty million people.
| Year | Virus Subtype | Nickname | Estimated Mortality |
| 1889 | H2N2 | NA | |
| 1900 | H3N8 | NA | |
| 1918 | H1N1 | Spanish Flu | 20 Million World Wide |
| 1957 | H2N2 | Asian Flu | 1 Million World Wide |
| 1968 | H3N2 | Hong Kong | 700,000 World Wide |
| 1977 | H1N1 | Russin Flu | NA |
In 1918 a new influenza subtype, the H1N1 subtype, caused the worst pandemic of the century. The H1N1 virus circulated until 1957 when it disappeared. Then, in 1977 it reappeared and has been circulating around the globe ever since. The H3N2 subtype is currently circulating along with the H1N1 subtype. It appeared in 1968 and produced a smaller pandemic then its circulating companion, but the H3N2 virus has continued to kill. Thousands have been killed by the H3N2 subtype in the use and it continues to be rather virulent
Last year, a new influenza subtype that previously was not known to infected humans was killing people in Hong Kong. The H5N1 virus, a former avian influenza subtype was infecting humans. It was found to be totally of avian origin and this meant that influenza was crossing the species barrier. Scientist were afraid that this deadly virus would mix with the human influenza virus and produce an easily spread killer. Chinese officials took the necessary precations to avoid this and the threat of a new pandemic from the killer "Bird Flu" seems to have subsided.
email: David Zage