Researchers found that identifying more than one in five carriers of carbapenem-resistant Enterobacteriaceae, or CRE, can “substantially dampen transmission” of the bacteria and should be the goal when identifying all carriers is not feasible.
Identifying fewer than one in five carriers “still leaves a significant number of CRE carriers unknown, and isolation of known carriers is not enough to meaningfully interrupt transmission,” Sarah M. Bartsch, MPH, a research associate at the Johns Hopkins Bloomberg School of Public Health, and colleagues wrote in The Journal of Infectious Diseases.
“The majority of CRE carriers are unknown since CRE typically is detected by testing done for clinical reasons, such as suspicion of an infection, and systematic screening is rarely performed outside of active outbreak settings. In other words, only a small fraction of all CRE carriers, the tip of the ‘iceberg,’ is known,” they wrote.
“Studies have shown that on average this tip of the iceberg may be only one out of every nine carriers; thus, the true CRE burden may be substantially higher than perceived. Knowing a greater proportion of the iceberg (eg, through universal or targeted screening) could lead to better prevention and control measures such as use of contact precautions and improved interfacility communication of CRE status.”
Bartsch and colleagues used a regional health care model of adult inpatient facilities in Orange County, California, to assess how knowing a greater proportion of CRE carriers would impact transmission and whether there is a key threshold to lessen transmission.
Results of the study showed that detecting and placing one in nine CRE carriers on contact precautions increased prevalence from 0% to 8% over 10 years, Bartsch and colleagues reported. They found that increasing the proportion of detected carriers yielded only linear reductions in transmission up to detecting one in five carriers.
“Substantial non-linear gains occur when more than one in five CRE carriers are detected,” they wrote. “This threshold represents a tipping point whereby a sufficient amount of the underlying CRE burden is known and placed under contact precautions to substantially dampen transmission.”
“While knowing all carriers certainly would provide the most benefits, if not feasible then it may be worthwhile to aim for detecting more than one in five carriers,” the authors concluded. “Detecting one in five carriers provided benefits particularly in conjunction with 80% contact precaution effectiveness. Effects of increased detection take at least a year and potentially many years to manifest and accrue over time.” – by Caitlyn Stulpin
Disclosures: Bartsch reports no relevant financial disclosures. Please see the study for all other authors’ relevant financial disclosures.