Susceptibility To Bird Flu May Depend On Your Genes

Featured Article
Main Category: Bird Flu / Avian Flu
Also Included In: Genetics;  Respiratory / Asthma
Article Date: 03 Nov 2006 - 12:00 PDT

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The reason some of us get bird flu infection and others don't may be down to our genetic make up, say experts from the World Health Organization (WHO), after analyzing information on the very rare cases of humans catching bird flu from other humans, where infection was only passed on to blood relatives.

In May 2006, seven people died of bird flu in North Sumatra, Indonesia. Some of them were infected by blood relatives - all the victims belonged to one extended family.

The scientists say this could eventually explain why humans do not catch it easily from birds/animals, and other humans.

The family shared a small room, an ideal condition for infected people to pass it on to other humans. Despite this, non-blood relatives, such as spouses, did not get ill.

Scientists fear the H5N1 bird flu virus strain could eventually mutate and become easily human transmissible - people could pass it on to other people easily. In order to do this, the virus would need to infect a person who has the normal human flu virus. The bird flu virus could then exchange genes with the normal human flu virus, and acquire its ability to spread easily among humans. If it managed to do this, we could be facing a serious global flu pandemic.

The 1918 flu pandemic, known as Spanish Flu, killed about 50 million people globally. It is believed to have evolved from a bird flu virus. A similar mutation today would probably spread much faster - we travel a lot more today than we used to in 1918.

Some scientists believe a mutated virus that could spread easily among humans would not be as deadly as the current H5N1 virus. This is because the current one has to get deep down into the human lung(s) to make a person ill - it does not infect the upper-respiratory tract, just the lower-respiratory tract. When an infected person coughs and/or sneezes, he/she does not emit many viruses (because they are so deep down). Hence, infecting another human is extremely difficult. In order to spread easily among humans it would need to infect the upper-respiratory tract. Upper-respiratory tract infections are easier to treat. Therefore, the theory goes, a mutated virus might infect many more people, but a lower percentage of cases would be fatal.

Bird flu = Avian Flu = Avian Influenza
H5N1 is a bird flu virus strain everyone is worried about. A high percentage of infected people die.

Written by: Christian Nordqvist
Editor: Medical News Today
Copyright: Medical News Today
Not to be reproduced without permission of Medical News Today

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