Preventing the spread of CRKP is key because the infections are so difficult to treat, the CDC's Srinivasan said. The "mainstay treatment," colistin, is an older generation antibiotic with toxic side effects. And newer, more effective treatment options are unlikely to be developed any time soon.
Although the report focuses on cases in L.A. county, CRKP was first noticed in New York City.
In a 2010 study by researchers at the Columbia University Medical Center in New York City, for instance, 42 percent of infected patients died within 30 days after infection.
"That's right, there are New York hospitals that have problems, North Carolina hospitals," Besser said. "It's not just limited to California."
The CDC website has a map detailing other affected states.
"If we want to stop resistant bacteria in their tracks, we have to know where to begin," the CDC's Srinivasan said in a statement.
"These findings demonstrate the vital need to monitor drug-resistant bacteria and highlight the important and growing role that state and local health departments are playing in helping monitor and prevent health care-associated infections."