Bird Flu Is Spreading in Alarming New Ways
H5N1 has infected cattle across the US and jumped from a mammal to a human for the first time. Experts fear it may someday evolve to spread among humans.
H5N1 has infected cattle across the US and jumped from a mammal to a human for the first time. Experts fear it may someday evolve to spread among humans.
Valley fever is thriving as California swings widely between drought and flooding.