Health
Tracking changes in avian influenza virus strains
NEWS IN BRIEF — Posted July 7, 2008
Some North American avian influenza strains -- specifically, certain A H7 virus strains -- have properties that may enhance their potential to infect humans as well as their potential to spread from human to human, according to study findings reported by Centers for Disease Control and Prevention researchers.
The study was published in the May 27 Proceedings of the National Academy of Sciences USA, and its lead author noted that its results underscore the importance of continued influenza virus surveillance.
These viruses infect humans by attaching to certain sugar receptor molecules on cells in the respiratory tract. The greater this ability to bind or attach, the more likely it is that the virus will cause illness in humans and possibly be transmitted from human to human, researchers said.
In this study, three recent H7N2 strains and two H7N3 strains from North America were tested and found to bind to both avian and human receptors in varying degrees.
One virus, an H7N2 strain isolated from an immune-compromised man in New York in 2003, was found to have the greatest binding to human sugar receptors. Overall, the findings suggest that these North American avian influenza A H7 viruses are partially adapted to recognize the sugar receptors preferred by human influenza viruses and found in the human upper respiratory tract.
Note: This item originally appeared at http://www.ama-assn.org/amednews/2008/07/07/hlbf0707.htm.
