The growing threat of antibiotic resistance and its repercussions has become a serious public health concern as the world continues to run out of antibiotics that are effective against these ever-changing pathogens.
Particularly troubling is a group of gram-negative bacteria referred to as carbapenem-resistant Enterobacteriaceae (CRE), which are associated with high morbidity and mortality, as they have proven highly resistant to most available antibiotics. In fact, some studies have found that CRE bacterial infections have a mortality rate as high as 50%. These bacteria are known to rapidly spread among patients in health care settings, and, as such, they are known to have been responsible for several deadly outbreaks in hospitals.
One of the ways in which these bacteria are known to attack is through central lines. In a recent analysis, investigators compared central line-associated bloodstream infections (CLABSIs) attributed to CRE in short-term acute care- (ACHs) with CLABSIs in long-term acute care hospitals (LTACHs) using pathogen and susceptibility data reported to the National Healthcare Safety Network (NHSN) from 2015 to 2016. They presented their findings at the SHEA Spring 2018 Conference.
“We defined CRE as any Klebsiella pneumoniae, Klebsiella oxytoca, Escherichia coli or Enterobacter spp that tested resistant to imipenem, meropenem, doripenem or ertapenem,” the authors wrote. “Susceptibility results were reported to NHSN as susceptible, intermediate, resistant, or not tested.”
For each pathogen by facility type, the investigators calculated a pooled mean percentage of resistant pathogens by dividing the sum of pathogens that tested resistant by the sum of pathogens tested.
The results showed that a total of 13,996 CLABSIs associated with the aforementioned pathogens were reported to the NHSN from both ACHs and LTACHs. The most prevalent CLABSI-causing pathogen was Klebsiella spp, which was responsible for 6172 infections (44% of all infections).
When looking specifically at ACHs, the investigators found that in 2015, 6438 CLABSIs were reported, whereas slightly less were reported in the following year (6113); however, 77% of all isolates were tested for carbapenem resistance (CR), and the investigators found that the overall resistance percentage increased from 4.7% in 2015 to 5.3% in 2016. Specifically, CR increased by 0.2%, 0.8%, and 1.0% in E. coli, Enterobacter, and Klebsiella spp, respectively.
A total of 787 CLABSIs were reported in 2015 in LTACHs; again, slightly less (658) were reported the following year. The authors report that about 88% of the isolates were tested, and the overall resistance percentage in LTACHs appeared to be much higher compared with ACHs. However, the resistance percentage decreased from 18.5% in 2015 to 15.8% in 2016; whereas CR increased in Enterobacter by 3.7%, CR decreased in E. coli and Klebsiella by 3.2% and 2.4%, respectively.
Despite the noted decrease, more CLABSI CRE were found in LTACHs compared with ACHs. “This could be explained by different patient populations and levels of care between the settings,” authors of the poster concluded.
The authors attributed the decline to improvements made in infection control policies and interventions among patients and staff. These interventions include CRE screening, contact precautions, as well as chlorhexidine baths.