Bird flu: What the 9 human cases in the U.S. so far tell us about the disease

What scientists know about bird flu symptoms from the first 9 U.S. human cases (nbcnews.com)

What the 9 human cases of bird flu in the U.S. so far tell us about the disease The illnesses, all in farm workers, have been relatively mild — a contrast to the flu’s deadly effect on many birds and some mammals. NBC News

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Experts still worry, though, that the virus could someday mutate into a version that causes more severe disease or that spreads from person to person. (So far, all transmission has been from animals to humans.)

“The concern is that as more animals are infected, and then more people are infected, the virus will change,” Binnicker said.

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