Trends in Resistance to Carbapenems and Third-Generation Cephalosporins among Clinical Isolates of Klebsiella pneumoniae in the United States, 1999-2010

Increases in the prevalence of drug-resistant pneumonia present a major infection control challenge for public health.

After broad-spectrum cephalosporins were widely adopted in the 1980s, multi-drug resistant pathogens such as carbapenem-resistant Klebsiella pneumoniae (CRKP) have emerged, presenting a threat to public health.

To better understand the trends in CRKP, researchers studied surveillance data from acute long-term care and outpatient settings across different geographic regions between 1999 and 2010. Results for 553,250 Klebsiella pneumoniae isolates were tested.

Key Findings:

  • Overall, elderly (65 years of age and older) showed the highest prevalence of carbapenem resistance—3.3 times that of pediatric patients (under age 18).
  • Cultures obtained from nursing homes were four times more likely to be third-generation CRKP than those from outpatient settings.
  • Cultures of Klebsiella pneumoniae from the northeastern United States were nine times as likely to be CRKP as those from the western United States.
  • Over the study period, South Atlantic states had the largest increase in third-generation CRKP (from 3.45% in 1999 to 13.46% in 2010), a nearly four-fold increase.

The researchers call the increase in the prevalence of drug-resistant strains in the non-acute setting “especially troubling,” as it may indicate a community-based epidemic. More laboratory capacity and coordinated surveillance strategies are needed to contain further spread of such emerging pathogens. The authors conclude,“Public health authorities should take notice of successful locally and nationally coordinated strategies for managing outbreaks and consider making CRKP a reportable disease.”