A woman is hospitalized in Wyoming with H5N1 bird flu, likely the result of handling infected birds in a backyard flock, health officials say.

An older woman in southeast Wyoming is hospitalized with bird flu, state health department officials said Friday. It's the state's first human case of Type A H5N1 influenza, which is spreading through animals and some people.

The new study is more evidence that the official U.S. tally of confirmed human bird flu infections—68 in the past year—is likely a significant undercount.