Antibiotic Resistant Bacteria Increase in South East US Community Hospitals Interview with:
Dr Joshua Thaden MD, PhD
Duke University Division of Infectious Diseases
Durham, North Carolina

Medical Research: What are the main findings of the study?

Dr. Thaden: The primary findings of the study are that

  • The rate of detection of particularly antibiotic resistant bacteria — the carbapenem-resistant Enterobacteriaceae (CRE) — has increased 5-fold in a set of community hospitals in the southeastern United States, and that
  • This increase is due to both changes in how we detect CRE and in increased endemicity (i.e., there are just more CRE around).

Medical Research: Were any of the findings unexpected?

Dr. Thaden:

  • First, the degree to which CRE detection increased was quite alarming. The five-fold increase in CRE detection over a relatively short period (2008-2012) was unexpected, particularly in small, community hospitals. We sometimes imagine that highly antibiotic resistant bacteria are primarily a problem at large, tertiary medical centers, but as we illustrated in this study this is clearly not the case. Antibiotic resistance is a major problem in the smaller, community hospitals as well, and we all need to remain vigilant.
  • Second, the degree to which hospital microbiology laboratory practices affected CRE detection was also quite surprising. There is a center called the Clinical and Laboratory and Standards Institute (CLSI) that makes recommendations on how to detect bacteria such as CRE. In our study, only 20% (5 out of 25) of hospitals had adopted the most recent CLSI guidelines regarding detection of CRE. We demonstrated that adopting the newer guidelines is hugely important in making sure that all CRE are found. In hospitals that adopted these guidelines, for example, we found that the CRE detection rate increased from 0.5 CRE per 100,000 patient days before implementation of new CLSI guidelines, to 4.1 CRE per 100,000 patient days after the guidelines were implemented. Thus, there are sure to be many CRE that are slipping through the cracks in our surveillance net in those hospitals that have not yet adopted the new CLSI carbapenem breakpoints.

Medical Research: What should clinicians and patients take away from your report?

Dr. Thaden: There are several messages to glean from the study.

  • First, the methods for detecting CRE need to improve. As noted above, only 20% of community hospitals in our study had adopted the most recent CLSI guidelines regarding CRE detection, and so there are many CRE that are slipping through our surveillance net. We cannot control the spread of CRE if they remain undetected.
  • Second, once detected, there needs to be a swift and centralized response. A hospital’s infection control team and the state laboratory should be notified so that a plan can be developed to prevent spread to other patients.
  • Third, there is still a great amount of research that needs to be done in order to identify effective strategies for slowing the spread of CRE and understanding the genetic basis for the spread of carbapenem-resistance.

Medical Research: What recommendations do you have for future research as a result of this study?

Dr. Thaden: Moving forward, one important area of research will be to examine the genetics of carbapenem-resistance in bacteria from community hospitals. There are many different enzymes and molecular mechanisms by which Enterobacteriaceae can become resistant to the carbapenem antibiotics, and understanding how bacteria are generating and passing on carbapenem resistance will be critical in understanding and controlling CRE. Another important area of research involves the study of public health measures to prevent spread of CRE. The CDC has outlined some basic strategies to decrease transmission, including hand hygiene, contact precautions, healthcare personnel education, limitation of medical device use, patient and staff cohorting, laboratory notification strategies, antimicrobial stewardship, and CRE active screening, though more research is necessary determine the effectiveness of these and other interventions so that we can develop a comprehensive and efficacious strategy for preventing the spread of CRE.


Rising Rates of Carbapenem-Resistant Enterobacteriaceae in Community Hospitals: A Mixed-Methods Review of Epidemiology and Microbiology Practices in a Network of Community Hospitals in the Southeastern United States

Joshua T. Thaden, MD, PhD,Sarah S. Lewis, MD, Kevin C. Hazen, PhD, Kirk Huslage, BSN, MSPH, Vance G. Fowler Jr, MD, MHS,Rebekah W. Moehring, MD, MPH, Luke F. Chen, MBBS, MPH,Constance D. Jones, RN, CIC,Zack S. Moore, MD, MPH, Daniel J. Sexton, MD, and Deverick J. Anderson, MD, MPH
Infection Control and Hospital Epidemiol…      Vol. 35, No. 8, August 2014  

Last Updated on July 18, 2014 by Marie Benz MD FAAD