Bird flu was busy in South Dakota and in some surrounding states in December. According to the USDA’s avian flu tracker, as of Friday, more than 400,000 turkeys in South Dakota and more than 4 million ...

The agency, in its latest update released Thursday, said the mutations were not found in samples taken from wild birds, suggesting the virus changed over the course of the patient’s infection.

The CDC warns samples of the bird flu virus show signs of mutations that could make it more transmissible to humans. The CDC ...