Science Saturday I: Avian Flu and You

News of the spread of the avian flu virus seems to get worse by the week as it hopscotches across the globe from its Third World roots. But two groups of researchers say they believe that the virus is rarely -- if ever -- transmitted from one person to another and have discovered why that apparently is so.

The Japanese and Dutch scientists say that the cells bearing the type of receptor the avian virus is known to favor are clustered in the deepest branches of the human respiratory tract, keeping it from spreading by coughs and sneezes. Human flu viruses typically infect cells in the upper respiratory tract.

The avian flu virus (see photo) would need to accumulate many mutations in its genetic material before it could become a pandemic strain, according to Yoshihiro Kawaoka, a virologist at the University of Tokyo and the University of Wisconsin. According to a Wisconsin press release:

The finding suggests that scientists and public health agencies worldwide may have more time to prepare for an eventual pandemic.

More time, but perhaps not enough as most virologists believe that a flu pandemic will happen sooner or later.

The avian flu virus, one of the 16 types of flu virus in the animal world, is still the most likely candidate for a pandemic because it is believe it eventually will manage to switch hosts and grow and spread in humans.

Peter Palese, a virologist at the Mount Sinai School of Medicine, says he did not believe the virus could infect people except when they were exposed to large doses, for example, by sleeping in the same room as chickens.

I feel strongly that [the virus] has been around in humans for a long time and never caused a pandemic, suggesting that this is not the virus which is likely to be the next pandemic.

But he added:

People have to understand we are not really prepared should it come.

For a bit more, go to myDNA here. For a whole lot more, go to Nature magazine here (registration required).