Bird Flu Virus Ten Times Worse for Lungs Than Normal Flu Virus

Featured Article
Main Category: Bird Flu / Avian Flu
Also Included In: Flu / Cold / SARS
Article Date: 11 Nov 2005 - 5:00 PDT

email to a friend   printer friendly   opinions  

Scientists say the H5N1 Bird Flu strain is ten times more powerful at inducing inflammation in the lungs than the normal human flu virus - this is why it is so deadly to humans. The inflammation is so fast that it causes serious destruction of the cells that line the lungs. 50% of humans infected with this bird flu strain die.

You can read about this report in the journal Science.

It's the H5N1 Bird Flu strain's virulence that worries health professionals.

At the moment humans cannot become infected easily. Bird flu spreads rapidly among birds, since 2003, 100 million birds have died. In this same period only 124 humans have been infected, of which 63 died. All the human cases have happened in South East Asia.

For a human to catch bird flu, he/she needs to have a lot of contact with infected birds (mainly poultry). Even then, infection rates are very low. A person with bird flu can infect another person, but this is extremely rare.

If the H5N1 Bird Flu virus were to mutate (and viruses do), it could learn to spread among humans. If this were to happen we could be facing a serious global health problem - a flu pandemic.

In 1918 Spanish Flu killed over 40 million people. It was a flu pandemic. The pandemic spread around the world with eleven months. At that time the world population was only one quarter of what it is now. In 1918 hardly anyone travelled by plane - now, millions of people travel around the globe each day. A flu pandemic now would spread around the world within a matter of weeks.

It is crucial that all countries work together to contain the spread of this virus. Experts around the globe agree that a flu pandemic will come. We don't know when, but there is a lot we can do to delay its onset. The more we can delay its spread, the more time we have to get medications and vaccines made and distributed.

At the moment there is one drug that can help infected patients survive. It is an antiviral drug called Tamiflu. It has to be given to the patient very early on during the illness, otherwise it is not effective. N.B. Tamiflu is not a vaccine, the patient takes it when he/she is infected.

How might the H5N1 virus mutate start a flu pandemic?

The are various ways it could mutate. The fastest way would be if it infected a human who had the normal flu. The H5N1 virus could then exchange genes with the normal flu virus. It would pick up the ability to spread among humans (just like the normal flu virus does). However, each time it infected a human the damage to the lungs could be ten times worse than normal human flu. If we all had the flu vaccine it would be much harder for the H5N1 virus to infect a human with normal flu - it would find one eventually, but we would have more time. What we need is time.

We don't know what the mutated virus would be like. If it picked up the ability to spread among humans while keeping its current virulence, it would be deadly. However, it could also pick up other characteristics and lose some of its virulence. Experts say the total number of human deaths resulting from a flu pandemic could be 7 million (mild virus) to 300 million (deadly virus).

Written by: Christian Nordqvist
Editor: Medical News Today


Copyright: Medical News Today
Not to be reproduced without permission of Medical News Today

• Additional
• References
• Citations