Human Nose Too Cold for Bird Flu Virus FRIDAY May 15, 2009 --
The inside of the human nose is a bit too chilly for the H5N1
avian flu virus, perhaps explaining why the strain has so far
not spread easily between people, British and U.S. scientists
reported Friday. According to researchers from Imperial College
London and the University of North Carolina, the avian flu virus
thrives in the bird gut, where temperatures hover around 40
degrees Celsius (104 degrees Fahrenheit). In contrast, the
inside of the human nose -- typically the first site of
influenza infection for humans -- stays at about 32 degrees
Celsius (89.6 degrees Fahrenheit). Experiments suggest that
avian flu strains cannot grow and replicate in this cooler
environment, the researchers said, nor can they effectively kill
nearby cells. And when the team created a special mutant virus
-- a human flu virus with proteins added from an avian flu
strain -- this strain also struggled to survive and grow at 32
degrees C. This suggests that more than one