Deadly Flu Mutation Could Lead to Worst Pandemic in History
Leading scientists in the field of deadly flu epidemics are worried about what could be the granddaddy of them all, and say it could be right around the corner.
They're talking about the bird flu, also known as H7N9. Experts say it could be as bad as, or even more severe, than the worst global pandemic in recorded history. That was the Spanish flu outbreak of 1918, which killed an estimated 40 million people. That flu also originated in birds.