Thursday, October 06, 2005

1918: It Was Bird Flu

As worries about avian flu busy the medical community, scientists have, after several years of intensive research, unlocked the secret of the 1918 "Spanish Flu" pandemic that killed at least 50 million people: it was a form of bird flu.

The urgency of those questions inspired scientists to embark on a several-year quest to unearth lung tissue from victims of the 1918 flu and to analyze the viruses' genes. The task has been challenging. Some samples came from tissue saved from long-ago autopsies. Others came from people buried in Alaska and frozen by the permafrost.

In both types of samples, however, the amounts of virus were tiny -- usually just a single copy of DNA fragments. As a result, researchers had to use cutting-edge molecular biology methods to read the genetic codes.

Now they have succeeded. In an Oct. 6 paper in Nature, scientists, led by Jeffery K. Taubenberger of the Armed Forces Institute of Pathology, report that they have read the full genetic sequence of the 1918 virus, along with the codes of scores of other influenza strains, including the avian flu.

DEADLY QUALITIES. Simultaneously, a team at the Centers for Disease Control & Prevention wrote in a paper in the Oct. 7 issue of Science that they used the genetic information to recreate the deadly 1918 strain. They proved how virulent the virus was by giving it to mice. The mice quickly died.

The work of these two teams is more than just a scientific tour-de-force. It also opens the door to understanding why some flu strains are deadlier than others -- and to figuring out how a virus that originally infects only birds is able to evolve to target humans. Soon it should be possible to use this information to learn if today's flu strains are mutating in ways that could bring another pandemic.

Very interesting. Check it out.


Post a Comment

<< Home