According to scientists at St. Jude Children’s Research Hospital, Memphis, USA, all bird flu viruses they have investigated have a unique gene not found in human flu viruses. This unique gene may play a major role in making the H5N1 bird flu virus strain so virulent (potent, powerful).
The scientists have been analysing samples of over 11,000 flu viruses. Team leader, Dr T Webster says some of these samples date back to 1976 and come from all corners of the globe. 7,000 of these samples come from birds (bird flu viruses).
You can read about this study in the journal Science.
The avian version of the flu virus is what killed humans in Vietnam and Thailand, and was also the virus that killed an estimated 40 million people during the Spanish Flu pandemic of 1918.
So far, over 2,000 bird flu genes and 160 complete genomes have been identified by Dr Webster and his team after completing research into 300 bird flu viruses.
We do not know how long the H5N1 virus has been killing birds. The first human to die from H5N1 infection was in 1997. Nothing then happened for a few years until 2003 – since 2003 over 160 people have been infected, of which about half have died (since 2003 over 100 million birds have died of bird flu).
Scientists fear the H5N1 bird flu virus strain will mutate and become easily transmissible among humans. It may infect a person who has the human flu and exchange genes with the human flu virus, picking up from it the ability to spread from human-to-human.
Written by: Christian Nordqvist
Editor: Medical News Today