Epidemiology study of carbapenam-resistant enterobacteriaceae (CRE): A 30-months experience at a tertiary centre in Northern Malaysia

Abstract

Background: Carbapenam-resistant entrerobacteriaceae (CRE) is an emerging serious health threat worldwide however the treatment option is limited. Sultanah Bahiyah Hospital is a 900-bed tertiary hospital in Northern Malaysia. There has been a steady increase of CRE prevalence over the years. Objectives: To study the epidemiology of CRE, comparing the risk factors, antecedent exposure to antibiotics and related mortality. Methods and materials: Methods: A retrospective descriptive study was conducted on all clinical isolates of CRE from 2017 till July 2019 with molecular characterization of carbapenemase genes. Carbapenem non-susceptibility is confirmed by Etest based on CLSI breakpoints. Results: CRE samples reported before 2017 were scarce (less than 16 cases per-year). However, a total of 213 isolates were reported within the study period and the trend increased dramatically from 60 cases in 2017 to 95 cases in 2018;recorded a 56.7% increment and it continued to rise. Isolates were mainly from blood and urine, with similar distribution of 27.7% (59/213) followed by tissue 15% (32/213) and tracheal aspirate 10.3% (22/213). Majority of organisms were Klebsiella pneumoniae (71.8%) and Enterobacter sp (22.5%) followed by E. coli (5%). 59.3%(102/172) were NDM-producing CRE with only 4 isolates were IMP, 3 OXA-48 but no KPC was detected. The remaining 37.8% (65/172) were negative by PCR. Only 30% (64/213) of the patients with CRE required treatment, with mortality rate of 59.7%. This is inclusive of 26.6% (17/64) patients who succumbed before CRE was identified from clinical specimens. Analysis of risk factors showed that ICU (Intensive Care Unit) admission is associated with higher mortality (p= 0.008). All isolates were resistant to all generations of cephalosporins and carbapenems. About 80% of CRE-infected patients had prior exposure to either carbapenem (40%), Piperacillin-tazobactam (40%) or third-generation and fourth-generation cephalosporins (40%) before CRE detection. Conclusion: Majority of CRE isolates in our region are NDM-producers, treatment decision is hence challenging. ICU admission is an important risk factor for CRE acquisition. High suspicion for CRE infection should be considered in critically ill patients who have been exposed to broad spectrum antibiotics.