[14apr2006, The Why Files are another excellent source of science explanation, from the University of Wisconsin. Pam]
The bird flu has killed millions of birds and more than 60 people in Asia. So far, the virus does not seem to infect one person directly from another. …
Three strategies have been discussed to fight an avian influenza once it starts to spread between people: Drugs, quarantine, and vaccines.
Each strategy has major pitfalls….
There are 4 pages in this feature plus a bibliography and a credits page. Megan Anderson, project assistant; Terry Devitt, editor; S.V. Medaris, designer/illustrator; David Tenenbaum, feature writer; Amy Toburen, content development executive
Bird Flu: Spreading Fast. What’s Next?
©2006, University of Wisconsin, Board of Regents. Last modified: December 01, 2005 15:38:40 PM
This first article has a good graphic about immunity and the evolutionary changes needed for a bird infection to become a human infection.
Flu virus can undergo antigenic drift, the small change that explains why last year’s flu vaccine doesn’t work so well this year. Or it can go through antigenic shift, a major change in virus subtype that makes the virus look new to the immune system. After antigenic shift, the virus gets new H and N numbers: H stands for hemagglutinin, and N for neuraminidase; both are surface proteins that can be attacked by the immune system. Hemagglutinin comes in 16 flavors, and neuraminidase in nine.
H1N1 caused the 1918 epidemic; H3N2 caused the 1968 epidemic, and H5N1 is the bird flu that’s causing a globeful of fretting this year. H1N1 and H3N2 remain widespread, but because most people have gained some immunity after infection by these subtypes, the common flu is seldom deadly.
Learn more from The Why Files, an all-round great site from the University of Wisconsin for teachers of science, math, and engineering. The second article explains some of the “CSI” aspects of forensic epidemiology.