A worker arranges containers of chickens at a wholesale market on Thursday, April 4, 2013, in Shanghai, China. In a worrisome sign, a bird flu in China appears to have mutated so that it can spread

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A worker arranges containers of chickens at a wholesale market on Thursday, April 4, 2013, in Shanghai, China. 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. (AP Photo) less 

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Associated Press
Thu, Apr 4, 2013 8:27 PM EDT