It's not the first U.S. death from a near-ultimate superbug, but it's a reminder that unkillable bacteria are evolving and spreading, public health experts said.
"We have a shrinking world," said Randall Todd of the Washoe County, Nevada health department.
The woman, in her 70s, died last August. Tests showed she had been infected with an antibiotic-resistant bacterial group called carbapenem-resistant Enterobacteriaceae (CRE). Worse, this one carried a feared mutation called NDM-1.
CRE refers to a family of drug-resistant bacteria. They've evolved so that a whole class of antibiotics cannot kill them, making them into what are known as superbugs. If they get into the bloodstream and cause an infection, CRE germs kill half their victims.
The NDM-1 mutation makes it even more drug-resistant. While most CREs in the U.S. can be killed with some last-ditch antibiotics, those carrying this mutation resist even more types of antibiotic. Worse, it's often unpredictable which drug will work.
Luckily, quick-thinking hospital staff isolated her soon after she was admitted in August and no one else caught the infection, Dr. Lei Chen of the Washoe County Health District told NBC News.
Chen and colleagues described the case in the Centers for Disease Control and Prevention's weekly report on disease.