Risk of infection following colonization with carbapenem-resistant Enterobactericeae: A systematic review

Background Carbapenem-resistant Enterobacteriaceae (CRE) have emerged as important health care-associated pathogens. Colonization precedes infection but the risk of developing infection amongst those colonized with CRE is not clear. Methods We searched multiple databases for studies reporting rates of CRE-colonized patients subsequently developing infection. Results Ten studies fulfilled our inclusion criteria, including 1,806 patients used in our analysis. All studies were observational and conducted among adult inpatients. The cumulative rate of infection was 16.5% in our study. The most common site of infection was the lung, identified in half of patients, followed in decreasing frequency by urinary tract; primary bloodstream; and skin and soft tissue, including surgical sites. Colonization or infection by CRE prolonged stay and was associated with a 10% overall mortality in our analysis. Conclusion Our study results suggest an overall 16.5% risk of infection with CRE amongst patients colonized with CRE. Given the high mortality rate observed with CRE infection and the difficulty in treating these infections, research to investigate and develop strategies to eliminate the colonization state are needed.