The Associated Press
BEIJING — Scientists taking a first look at the genetics of a bird flu strain that has killed three people in China said April 3 that the virus could be harder to track than its better-known cousin H5N1 because it might be able to spread among poultry without showing any signs.
They said the virus is troubling because it can infect poultry without producing any symptoms, while seriously sickening humans. The virus, previously known to have infected only birds, appears to have mutated, enabling it to more easily infect other animals, including pigs, which could. . .

