667. Carbapenem-Resistant Klebsiella pneumoniae Producing New Delhi Metallo-Beta-Lactamase at an Acute-Care Hospital Denver, Colorado, 2012
Session: Oral Abstract Session: HAI Outbreaks Crossing Healthcare Settings
Friday, October 4, 2013: 11:15 AM
Room: The Moscone Center: 300
Background: Carbapenem-resistant Klebsiella pneumoniae(CRKP) are highly transmissible and can cause health care–associated infections with >40% mortality. New Delhi metallo-beta-lactamase (NDM)-producing CRKP are rare in the United States. After two patients at a Denver hospital were identified with NDM-producing CRKP during July–August 2012, an investigation was conducted to characterize the outbreak and prevent transmission.

Methods: CDC tested CRKP isolates by real-time polymerase chain reaction for blaNDM. A case had NDM-producing CRKP isolated from clinical or rectal active surveillance cultures (ASC) collected during January 1–October 30. Cases were identified through microbiology record reviews and six rounds of ASC on units where affected patients had resided. Medical records were reviewed for epidemiologic links; relatedness of CRKP isolates was evaluated by pulsed-field gel electrophoresis (PFGE) and whole-genome sequencing (WGS).

Results: A third patient, admitted in May, was identified through microbiology records review. ASC identified five additional cases. Patients were aged 23–75 years and had resided on 11 different units (median stay: 18 days; range: 12–83 days) before case identification; three were treated for infection; five were asymptomatically colonized, and none died. All isolates were highly related by PFGE. WGS suggested three clusters of CRKP. Combining WGS with epidemiology identified four units as likely transmission sites.  Acquisition of NDM-producing CRKP by some patients was not explained by direct epidemiologic overlap, suggesting that undetected, asymptomatically colonized patients were involved in transmission. 

Conclusion: A 4-month outbreak of NDM-producing CRKP occurred at one hospital, highlighting the risk for spread of these organisms. PFGE did not sufficiently differentiate among case isolates, but combining rapid WGS with epidemiologic links indicated transmission primarily occurred on four units and might be useful for guiding control measures in real time. Evidence that undetected asymptomatically colonized patients likely contributed to the outbreak highlights the importance of timely ASC combined with targeted infection prevention measures to control transmission.

Erin Epson, MD1, Joyanna Wendt, MD, MPH2, Larissa Pisney, M.D.3, Duncan MacCannell, PhD4, Sarah Jackson Janelle, MPH5, Brandon Kitchel, MS6, Heather O'Connell, PhD4, J. Kamile Rasheed, PhD7, Brandi Limbago, PhD7, Carolyn V. Gould, MD, MS6, Alexander Kallen, MD, MPH7, Michelle Barron, MD8 and Wendy Bamberg, MD9, (1)Communicable Diseases Epidemiology Section, Centers for Disease Control and Prevention assigned to the Colorado Department of Public Health and Environment, Denver, CO, (2)Division of Healthcare Quality Promotion, CDC, Atlanta, GA, (3)Infectious Diseases, University of Colorado Denver, Aurora, CO, (4)Division of Healthcare Quality Promotion, Centers for Disease Control and Prevention, Atlanta, GA, (5)Colorado Department of Public Health and Environment, Denver, CO, (6)Centers for Disease Control and Prevention, Atlanta, GA, (7)Division Of Healthcare Quality Promotion, Centers for Disease Control and Prevention, Atlanta, GA, (8)Internal Medicine/Infectious Diseases, University of Colorado Denver, Aurora, CO, (9)Colorado Dept. of Public Health and Environment, Denver, CO


E. Epson, None

J. Wendt, None

L. Pisney, None

D. MacCannell, None

S. Jackson Janelle, None

B. Kitchel, None

H. O'Connell, None

J. K. Rasheed, None

B. Limbago, None

C. V. Gould, None

A. Kallen, None

M. Barron, None

W. Bamberg, None

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