Evaluation of patient risk factors for infection with carbapenem-resistant Enterobacteriaceae

To evaluate risk factors for infection or colonization with carbapenem-resistant Enterobacteriaceae (CRE) to develop an algorithm for targeted CRE screening.

We conducted a case-control study of 50 CRE-positive cases and 100 CRE-negative controls to identify risk factors that were significant for CRE infection or colonization. The setting was at an acute care academic hospital. Patients who tested positive for CRE or other microbiological laboratory tests during the study period were included. We reviewed medical records of 50 patients who were CRE-positive and 100 matched controls who had a non-CRE culture at a similar anatomic site within the closest time period to the case's culture date. Risk factors were assessed using logistic regression with SAS 9.4, observing the 95% confidence interval (CI) to determine significance.

Significant risk factors for CRE infection or colonization included the use of fluoroquinolones (odds ratio [OR], 3.75; 95% CI, 1.35, 10.38) and cephalosporins (OR, 2.37; 95% CI, 1.17, 4.86). In addition, undergoing an invasive procedure with a scope device was also a significant risk factor for our participants (OR, 4.57; 95% CI, 1.31, 16.02). Significance of these risk factors varied within the community-acquired and hospital-acquired cases.

Our results suggest that exposure to certain antimicrobials and invasive procedures with a scope device (endoscopic retrograde cholangiopancreatography, duodenal endoscope) are risk factors for CRE. The findings of significant differences in antimicrobials received highlight the necessity to understand antimicrobial stewardship in the development of CRE colonization and infection. Along with antibiotics, inaccessibility to components within scope devices may be increasing the risk of CRE spread.