And while the new bug is highly resistant to drugs, it is not spreading rapidly -- at least not in the United States -- and it is not particularly deadly.
In fact, it is not actually a bug at all. Instead, the drug resistance comes from a gene called NDM-1 that gets passed from one kind of bacteria to another.
"Calling it a superbug doesn't quite make sense," said Stephen Calderwood, chief of the infectious disease division at Massachusetts General Hospital in Boston, who recently treated someone with the infection. "It is highly resistant, but it doesn't make someone more sick. And as far as we know, it doesn't more easily go from one person to another."
Rather than sparking fears of an imminent epidemic, he added, the arrival of the gene points to the need for new kinds of antibiotics, tighter controls on existing antibiotics in some places, better international cooperation on health prevention, and more careful controls on medical tourism.
"If you put this into context, there are some worrisome features that need close attention. But with the data available to date, we don't know how worrisome it will be," Calderwood said. "Drug resistance is a big problem. It's underappreciated, and it needs a new investment. This latest bug is just one more example. It's not that dramatically different."