New H5N1 papers--the clue's in the sugars

Actually being at a conference soaking up so much of this stuff means, alas, not nearly as much time as I usually spend during the week actually reading the new literature in many of the areas I write about. Over at Effect Measure, as usual, they help to make up for that, by commenting on two new papers in Science and Nature that give one potential reason why human-to-human transmission isn't occurring yet--but Revere notes it's not quite that simple.

(More after the jump)

The reason, the researchers propose, is 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 virus would need to accumulate many mutations in its genetic material before it could become a pandemic strain, said Yoshihiro Kawaoka, a virologist at the University of Tokyo and the University of Wisconsin.

According to a University of Wisconsin news release approved by Dr. Kawaoka, "The finding suggests that scientists and public health agencies worldwide may have more time to prepare for an eventual pandemic."

Revere has written previously on the receptors on our own cells that are important for influenza binding, and breaks down the papers into a nice digestible piece. Of course, it's not quite as simple as the NY Times headline for the story I linked ("Studies Suggest Avian Flu Pandemic Isn't Imminent") makes it out to be, and Revere is very good at pointing out where we lack information, and concludes that:

Contrary to the more optimistic interpretations, it is too early to conclude that H5N1 is not likely to be easily transmissible from person to person soley on account of its location deep in the lungs. The papers do not show this nor do they conclude this.

Check it out to find out what the new research really does mean.

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Hi Tara,

I wrote an article about it, too: Sugar, Sugar.

I summarized the papers and added a structure of a hemagglutinin bound to one of the sialic acids.

The Shinya paper has some nice staining that shows the receptors used by the avian virus, located in the alveoli, and few of those receptors in the nose and upper airway. It does make sense that it will be harder (not impossible, just harder) to spread viral particles if they have to travel a longer way to get out of the body.

Hi Tara
i noticed that the New York Times never uses the term
BIRD FLU , but always writes AVIAN INFLUENZA, never bird
flu.....why the need to say AVIAN FLU instead of BIRD FLU. do you know?

DANNY

By danny bee (not verified) on 26 Mar 2006 #permalink

Danny says:

i noticed that the New York Times never uses the term BIRD FLU , but always writes AVIAN INFLUENZA, never bird flu.....why the need to say AVIAN FLU instead of BIRD FLU. do you know?

Actually Danny, they use both. Plug 'bird flu source:new_york_times' into Google and click on 'News results ... ' and you'll see. 'Avian influenza' is the more scientificy term and 'bird flu' the more casual. They might use 'bird flu' in a article title simply because it's shorter and more clear to the average reader.