'Superbug' spreading to Southern California hospitals
A dangerous drug-resistant bacterium has spread to patients in Southern California, according to a study by Los Angeles County public health officials.
More than 350 cases of carbapenem-resistant Klebsiella pneumoniae, or CRKP, have been reported at healthcare facilities in Los Angeles County, mostly among elderly patients at skilled-nursing and long-term care facilities, according to a study by Dr. Dawn Terashita, an epidemiologist with the Los Angeles County Department of Public Health.
It was not clear from the study how many of the infections proved fatal, but other studies in the U.S. and Israel have shown that about 40% of patients with the infection die. Tereshita was not available for comment Thursday morning but was scheduled to speak about the study in the afternoon.
"These are very serious infections, hugely complicated by the fact that the treatment options are severely limited," said Dr. Arjun Srinivasan, associate director for healthcare-associated infection-prevention programs at the federal Centers for Disease Control and Prevention in Atlanta.
The L.A. County Department of Public Health describes CRKP as an antibiotic-resistant organism that "can cause infections in healthcare settings, including pneumonia, bloodstream infections, wound or surgical site infections, and meningitis."
Unlike other superbugs such as methicillin-resistant Staphylococcus aureus, or MRSA, the CRKP pathogen is an enterobacterium, in the same "lethal family" of bacteria as E. coli, Srinivasan said.
"We've been monitoring the rise of this organism for a few years at CDC," he said. "Initially, it was first described in North Carolina, and then we started getting reports in the New York and New Jersey area. We are seeing reports of this organism all over the country now."
He stressed that unlike MRSA and other superbugs, CRKP has not spread in communities but remains confined to healthcare facilities.
"The key is that it remains pretty rare in most places," he said, although, "there are pockets of the country where they are encountering this a lot, like New York City."
The superbug is usually treated with the antibiotic colistin, which is so strong it is often toxic to patients but in other cases has not proved strong enough to overcome the bacterium, Srinivasan said.
The CDC recommends an aggressive approach in preventing the spread of the bacterium, including isolating infected patients and testing those around them.
Prevention is key, Srinivasan said, including ensuring regular hand washing by healthcare workers and other basic infection-control measures.
Tereshita analyzed the results of patient tests the health department required hospitals and labs to submit June 1, 2010, to Dec. 31, 2010. Reports were filed by 102 hospitals and five labs.
Of the infections reported, 146 (42%) occurred at eight long-term acute-care hospitals, one of which had an outbreak.
An additional 20 cases were reported at skilled-nursing facilities.
The rest were reported at acute-care hospitals. Particular facilities were not identified in the report.
The mean age of patients who tested positive for the pathogen was 73, and more than half were female, the study showed.
Terashita concluded that CRKP was more common in Los Angeles County than public health officials had thought (possibly because cases had not been reported accurately), that hospitals need to do a better job of reporting infections and that healthcare facilities need to raise awareness about the bug to prevent the spread of infection.
"These patients tend to travel frequently between these and other healthcare facilities," she wrote.
Terashita's study had been embargoed for release at a conference of the Society for Healthcare Epidemiology of America in Dallas, beginning on April 1, but several news organizations decided to publish the results Thursday, citing the "public health concerns involved."
-- Molly Hennessy-Fiske and Howard Blume
Map: States colored yellow show confirmed CRE cases caused by the KPC enzyme in 2010. A blue dot represents a confirmation of NRE caused by NDM-1 enzyme. An orange dot represents a CRE caused by a VIM or IMP enzyme. Credit: CDC