Outcomes of Carbapenem-Resistant Klebsiella pneumoniae Infection and the Impact of Antimicrobial and Adjunctive Therapies

Patel, Gopi MD
Huprikar, Shirish MD
Factor, Stephanie H. MD, MPH
Jenkins, Stephen G. PhD
Calfee, David P. MD, MS

From the Departments of Medicine (G.P., S.H., S.H.F., S.G.J., D.P.C.) and Pathology (S.G.J.), Mount Sinai School of Medicine, New York, New York.

Address reprint requests to David P. Calfee, MD, MS, Mount Sinai School of Medicine, One Gustave L. Levy Place, Box 1151, New York, NY 10029 ([email protected]).

Received April 21, 2008; accepted July 24, 2008; electronically published October 30, 2008.

Infection Control and Hospital Epidemiology 29(12):p 1099-1106, December 2008.

BACKGROUND

Carbapenem-resistant Klebsiella pneumoniae is an emerging healthcare-associated pathogen.

OBJECTIVE

To describe the epidemiology of and clinical outcomes associated with carbapenem-resistant K. pneumoniae infection and to identify risk factors associated with mortality among patients with this type of infection.

SETTING

Mount Sinai Hospital, a 1,171-bed tertiary care teaching hospital in New York City.

DESIGN

Two matched case-control studies.

METHODS

In the first matched case-control study, case patients with carbapenem-resistant K. pneumoniae infection were compared with control patients with carbapenem-susceptible K. pneumoniae infection. In the second case-control study, patients who survived carbapenem-resistant K. pneumoniae infection were compared with those who did not survive, to identify risk factors associated with mortality among patients with carbapenem-resistant K. pneumoniae infection.

RESULTS

There were 99 case patients and 99 control patients identified. Carbapenem-resistant K. pneumoniae infection was independently associated with recent organ or stem-cell transplantation (P=.008), receipt of mechanical ventilation (P=.04), longer length of stay before infection (P=.01), and exposure to cephalosporins (P=.02) and carbapenems (P<.001). Case patients were more likely than control patients to die during hospitalization (48% vs 20%; P<.001) and to die from infection (38% vs 12%; P<.001). Removal of the focus of infection (ie, debridement) was independently associated with patient survival (P=.002). The timely administration of antibiotics with in vitro activity against carbapenem-resistant K. pneumoniae was not associated with patient survival.

CONCLUSIONS

Carbapenem-resistant K. pneumoniae infection is associated with numerous healthcare-related risk factors and with high mortality. The mortality rate associated with carbapenem-resistant K. pneumoniae infection and the limited antimicrobial options for treatment of carbapenem-resistant K. pneumoniae infection highlight the need for improved detection of carbapenem-resistant K. pneumoniae infection, identification of effective preventive measures, and development of novel agents with reliable clinical efficacy against carbapenem-resistant K. pneumoniae.