Lets know more about Bird Flu - Past Pandemics

[chetnarayan]

Bird Flu - Past Pandemics

Influenza Pandemics

The 20th century saw the emergence of several new influenza A virus subtypes that caused three pandemics, all of which spread around the world within a year of being detected. Here's a quick review of the three pandemics:
1. In 1918-19 the "Spanish flu" [A (H1N1)] caused the highest number of known influenza deaths. However, the actual influenza virus subtype was not detected in the 1918-19 pandemic. More than 500,000 people died in the United States alone, and up to an estimated of 50 million people may have lost their lives worldwide. Many died within the first few days after infection, while others died of secondary complications. Nearly half of those who perished were young, healthy adults. Influenza A (H1N1) viruses still circulate today after being introduced again into the human population in 1977.
2. In 1957-58 the "Asian flu" [A (H2N2)] caused about 70,000 deaths in the United States. The virus was first identified in China in late February 1957 and by June 1957, the Asian flu had spread to the United States.
3. In 1968-69 the "Hong Kong flu," [A (H3N2)] caused about 34,000 deaths in the United States. The virus was first detected in Hong Kong in early 1968 and arrived in the United States later that same year. Influenza A (H3N2) viruses still circulate today.
Both the 1957-58 and 1968-69 pandemics were caused by viruses containing a combination of genes from a human influenza virus and an avian (derived from birds) influenza virus. The 1918-19 pandemic virus appears to have an avian origin.
What do these past pandemics tell us? It could happen again, could be tomorrow, later this year, next year or even 5 years later. No matter what, we cannot take chances.







>>>>>>>>>>>>>>>>>