Leading scientists in Hong Kong have found that the H5N1 bird flu virus can infect cells in the upper airway of humans and need not penetrate deep in the lungs to cause infection.
A study by scientists based in the United States in 2006 suggested that H5N1 could not infect people easily because it had to first lodge itself deep inside the lungs, where it binds more easily to certain receptors called the alpha 2-3.
But in an article published in the January issue of the journal Nature Medicine, scientists from the University of Hong Kong found that the virus could infect the nasopharynx, an area behind the nose and above the soft palate, and the throat.
"It is still not able in most cases to establish infection and has not been able to transmit human to human [efficiently]. It doesn't change that situation as such," microbiology professor Malik Peiris said.
