BEIJING - In a worrisome sign, a bird flu in China appears to have mutated so that it can spread to other animals, raising the potential for a bigger threat to people, scientists said Wednesday.
So far, the flu has sickened nine people in China and killed three. It's not clear how they became infected, but there's no evidence the virus is spreading easily among people.
But the virus can, evidently, move through poultry without making them sick, experts said, making it difficult to track the germ in flocks. The findings are preliminary and need further testing.
In the wake of the illnesses, the Chinese Center for Disease Control and Prevention shared the genetic sequence of the H7N9 virus with other scientists to help study how the virus might behave in different animals and situations.