At least for now, chickens, turkeys and other fowl are the only direct targets of the avian flu outbreak that has spread across the U.S. Yet scientists say there is a subtype of the virus that may have the potential to become a human pandemic.

The outbreak, which the U.S. Department of Agriculture says has affected 20 states, has resulted in the destruction of at least 6 million chickens and turkeys and has put upward pressure on poultry prices. It has also triggered fears that much worse could be in store.

Daniel Janies, professor of bioinformatics and genomics at the University of North Carolina at Charlotte who co-authored a paper this year on the spread of an avian influenza, admits it’s “hard to say” whether the flu could make the jump from contained to catastrophe. Still, according to his research, bird flu has the potential to be “highly pathogenic and periodically infect humans.” FULL REPORT