The Centers for Disease Control and Prevention just released a surveillance report describing national estimates of antimicrobial resistance among health care–associated infections (HAIs) in hospitals. The report compiles HAI data submitted to the CDC’s National Healthcare Safety Network (NHSN) from almost all short-term acute care hospitals, inpatient rehabilitation facilities, and long-term acute care hospitals in the country.
These data highlight the broad reach and urgent nature of the drug resistance problem challenging clinicians today; resistance is occurring across different types of infections and patient populations, and dangerous resistance profiles such as carbapenem-resistant Enterobacteriaceae, or CRE, are not going away.
Lindsey Weiner
The report highlights the percentage of HAI organisms that were resistant to select antibiotics for 21 different bug-drug combinations from 2011 to 2014. Most noticeable across this time period was an increase in the percentage of Escherichia coli that tested resistant to extended-spectrum cephalosporins, fluoroquinolones, and were identified as multidrug resistant (Infect Control Hosp Epidemiol. 2016 Aug 30. doi: 10.1017/ice.2016.174).
In 2011, 41.1% of E. coli central line–associated bloodstream infections (CLABSIs) were resistant to fluoroquinolones; this percentage increased to 49.3% by 2014. And, among catheter-associated UTIs (CAUTIs), 8% of E. coli were identified as multidrug resistant in 2014, an increase from 5.5% in 2011.
Hospitals continue to report CRE infections, which are often untreatable and represent a serious public health threat. Across the major HAI types analyzed in this report, CRE were found in CLABSIs (7.1% of Enterobacteriaceae were resistant to carbapenems), CAUTIs (4.0% resistant), and surgical site infections (1.8% resistant). After taking a closer look at individual species of bacteria, we found that almost 11% of CLABSIs caused by Klebsiella species were resistant to carbapenems, which was the highest resistance among all Enterobacteriaceae species. Furthermore, Enterobacter species showed increasing resistance to carbapenems, as the percentage resistant in CLABSIs increased from 3.0% in 2011 to 6.6% in 2014.
These data underscore the urgent nature of CRE prevention efforts, and fighting back against these deadly bacteria will require collaborative efforts from the entire health care community including health care facility leaders, health care providers, and state and local health departments.
Antibiotic-resistant infections are an important patient safety issue and continue to pose a threat to modern medicine. There are small improvements in some phenotypes such as multidrug-resistant Acinetobacter, in which the percentage resistant in CLABSIs decreased from 60.9% in 2011 to 43.7% in 2014. Multidrug-resistant Klebsiella appears to be declining as well, from 20.9% resistant to 17.2%. Despite some improvements, the data in this report support the conclusion that much more work is needed to combat antibiotic resistance. The CDC has identified three critical efforts to slow the spread of resistant HAIs:
• Prevent infections related to devices and surgeries.
• Prevent the spread of bacteria between patients and between facilities.
• Improve antibiotic use in health care settings.
In addition to drug resistance, this report looked at the frequency of pathogens causing HAIs. The No. 1 and No. 3 most common pathogens among all HAIs were E.coli and Klebsiella, both of which are gram-negative bacteria with the propensity to develop antibiotic resistance.
The data also help identify important differences in the causes of HAIs across each of the infection types. For example, CLABSIs were more commonly due to gram positive organisms and Candida (a fungus), while surgical site infections (SSIs) were most frequently caused by Staph aureus. NHSN tracks SSIs following 39 different types of procedures, and while Staph aureus was the most common pathogen reported overall, the pathogen distributions did vary by surgery site. For example, almost 30% of SSIs following transplant procedures were caused by a species of Enterococcus.
Obviously, there’s far more data in the report than we can discuss here. Fortunately, the CDC’s new Antibiotic Resistance Patient Safety Atlas gives everyone an opportunity to explore these resistance patterns further; color-coded maps and charts included within the Atlas can help you identify common resistance phenotypes in your state and region. While these data give us a national snapshot of resistance profiles, we know there is wide variation among individual health care settings. It is important for providers to become familiar with the common pathogens and resistance profiles in their hospitals and recognize that common infecting organisms vary across different types of infections.
This report underscores the important challenges posed by resistant organisms in hospitals. Combating antibiotic resistance is a top public health priority in the United States and around the world, and having data to direct action is a key part of tackling the problem.
The CDC will continue to use and expand its efforts to monitor antibiotic resistance through surveillance systems such as NHSN, and will remain committed to providing data to support the health care community in efforts to reduce the spread of resistance and improve antibiotic use.
Lindsey Weiner, MPH, is an epidemiologist and associate service fellow in the Surveillance Branch, Division of Healthcare Quality Promotion, at the Centers for Disease Control and Prevention.