"horrifyingly real"

The film "Contagion" may have been fiction, but the 1918-19 influenza epidemic was horrifyingly real. The "Spanish flu" epidemic tore a path of destruction across the globe, killing an estimated 50-100 million people within months before disappearing into history.

Now, evidence from U.S. soldiers felled by the virus reveals that it circulated in the country for four months before the pandemic was even identified.

The findings, published online Monday in the journal Proceedings of the National Academy of Sciences, offer a picture of a virus as it turned from common pathogen to killer bug, said senior author Jeffery Taubenberger, a pathologist at the National Institute of Allergy and Infectious Diseases in Bethesda, Md.