The history of the bird flu and similar viruses could be the greatest warning we need to take a potential bird flu pandemic seriously.
If the current strain of avian influenza mutates to a human to human bird flu history suggests tens of millions of people could die.
And the only practical every day precaution effective at preventing a repeat of the dreadful bird flu history of the past could be effective hand hygiene.
Bird flu history goes back to the early 1900s.
Recently the US Centers for disease control obtained virus samples from the dead bodies of victims of the 1918 Spanish flu.
The results of this research suggest the Spanish flu virus that broke out in 1918 probably started as a bird flu too.
This is alarming news because the Spanish flu killed from 20 to 50 million people.
A similar virus today could be much worse because our population densities are so much higher and people regularly travel across the world in less than a day.
The history of the bird flu supports David Nabaro's estimate that a mutated human to human bird flu virus could kill between 5 million and 150 million people.
Many now see health authority warnings as bird flu hype.
But medical authorities have seen a fast spreading killer virus a major global health threat for decades and the current strain of bird flu has been impossible to contain spreading across Asia and Europe with migrating birds.
This rapid spread is increasing the chance that the bird flu virus will mutate to a human to human virus repeating the gruesome history of the Spanish flu pandemic of 1918.
The history of the bird flu is more recent and even more alarming according to Britain's chief medical officer Sir Liam Donaldson.
Sir Liam said in a BBC interview that it wasn't a question of if a virus like the bird flu would hit but when.
He said history shows us that a bird flu virus can combine with a human virus very easily.
And an unusual strain of influenza is likely to kill many people because the general population hasn't had a chance to build a natural resistance to viruses that come from unusual sources like birds.
Influenza viruses like the bird flu created dreadful history in 1918 with the Spanish flu, 1958 with the Asian flu pandemic and in 1968 with the Hong Kong flu.
Sir Liam also pointed out that times have changed since the Spanish flu of 1918.
We won't have an effective vaccine until after the bird flu virus mutates and that will take several months to produce for a large population – if it can be produced before the virus mutates again making the vaccine ineffective.
But we do have antiviral drugs, hospital facilities, intensive care and antibiotics.
We also have improved public amenities like running water and improved hygiene and hygiene may be the first and most practical line of defense against killer viruses like the bird flu.
Over 90% of viruses like the bird flu enter our bodies through contact between the mucous membranes of the eyes and nose and the fingernails.
Learning effective hand washing is recommended by all major health authorities including the World Health Organisation as a basic bird flu prevention.
Read the FREE report How To Prevent Bird Flu and learn more about how you can use effective hand washing and other advanced hygiene practices to reduce your chance of catching killer viruses.
Free download at http://www.howtopreventbirdflu.com
More on the history of the bird flu at http://history.flu-bird.com