A step forward for bird flu research

Two independent research teams have discovered why it is difficult for bird flu to pass easily between people, according to an article published Wednesday on the New Scientist website.

Whereas most flu viruses bind to cells in the upper respiratory tract, the H5N1 bird flu strain – which has now killed over 100 people – binds to cells deep in the lungs. Because of this, viral particles do not get released into the air when an infected person coughs or sneezes. This makes the virus less able to infect others.

These recent findings might also explain why the bird flu is so deadly. The particular lung cells that the virus binds to are active in lung tissue repair. By binding to the cells, the virus can hijack their ability to work properly and keep the lungs healthy. The virus also binds to white blood cells in the lungs, which serve to increase inflammation and make bird flu-induced pneumonia even more dangerous.

This new information may help virologists understand what types of mutations, or genetic changes, the virus might undergo next – and which ones would make it more lethal. A mutation that caused the virus to bind to cells in the nose or throat, for example, could be catastrophic.

Armed with this new knowledge, scientists will have a better idea of what to watch for as the virus continues to spread around the globe.

Original research articles published here (Nature) and here (Science). Registration is required for full access.