FLU HISTORY 101
Looking at the past can help us understand our world today, and this principle applies to avian influenza. Many scientists and health experts rely on information from past pandemics, such as the Spanish Flu, to help them understand the current situation. Before we delve into historical detail, here are some facts you should know...
Gravestone of a victim that died of the
Spanish Flu (Lynn Johnson)
- Avian influenza was first identified in Italy in 1878, and was initially known as the fowl plague.
- Avian influenza can be traced to five host-specific virus families: ancient equine, recent equine, gull, swine, and human.
- The ancestor of human and classic swine viruses is a virus that contained genes from avian sources.
- Historical patterns indicate that an average of three to four influenza pandemics occur each century.
- Scientists have found that avian influenza viruses in their natural reservoirs have reached their 'optimum'; they have not shown signs of evolution for over sixty years.
- " In the nineteenth century, three major pandemics took place, mostly around Europe: in 1830-33, 1847, and the Russian Flu in 1889-90.
- In the twentieth century, pandemics have occurred three times: in 1918-19, 1957-58, and in 1968-69.
- Ten pandemics have taken place in the past 300 years; the last pandemic was the Hong Kong Flu in 1968.
A CLOSER LOOK: Major Influenza Outbreaks
In the past 200 years, we have had several major pandemics. Below is a table featuring the important pandemics, beginning during the 1890s.
| Era | Origin | Virus Subtype | Mode of Antigenic Shift | |
|---|---|---|---|---|
| Source: The Monster at Our Door/Mike Davis | ||||
| 1890s | Guangdong | H2N2 | Not known | |
| 1900s | Not known | H3N8 | Not known | |
| 1918-1957 | Kansas, France, or China | H1N1 | Species jump or recombination | |
| 1957-1968 | Yunnan | H2N2 | Reassortment (pig?) | |
| 1968-Present | Guangdong | H3N2 | Reassortment (pig?) | |
| 1977-Present | China or Russia | H1N1 | Reintroduction from cryptic reservoir | |
| 1997 | Guangdong | H5N1 | Species jump | |
In the next three sections, we will look at the major pandemics of the last century: the Spanish Flu, the Asian Flu, and the Hong Kong Flu. In addition, we will examine influenza discoveries and breakthroughs up to 1997.