Enterobacteriaceae infections in Saudi Arabia: a regression analysis

Abstract

Background: Carbapenem-resistant Enterobacteriaceae (CRE) are multidrug-resistant microorganisms. Infections caused by these microorganisms have limited treatment options, frequently leading to high mortality rates. Objective: This study aimed to identify the microbiological and clinical characteristics of CRE infections among hospitalized patients in a university hospital, and included treatment regimens, duration, infection-related mortality, and risk factors associated with death. Methods: the study analyzed the consecutive CRE infections in patients admitted to King Abdulaziz University Hospital (Jeddah, Saudi Arabia) between January 2014 and December 2016. Patients’ records for CRE infections at any sterile site during the study period were reviewed to analyze patient demographics, CRE risk factors, comorbidities, site of infection, antibiotic treatment, and septic shock. Therapeutic regimens including monotherapies, combination therapies, as well as different durations of treatment were also reviewed. The clinical outcome in this study was 30-day mortality. Statistical analyses were conducted by IBM© SPSS© Statistics version 21 using multiple logistic regression model, Chi-square, independent-sample t-test, and Fisher’s exact test. A p value of ≤0.05 was considered significant. Results: Klebsiella pneumoniae was the most frequently (89.8%) isolated organism. Chest (22%) and urinary tract infections (22%) were the main sources of CRE infections. Combined therapy resulted in significantly more deaths than the monotherapy (p=0.005). By logistic regression, the significant predictors were septic shock (Odds ratio=8.82), Charlson Comorbidity index (CCI) of two (Odds ratio=2.39) and renal impairment (Odds ratio=4.4). About 66% of patients for whom the antibiotics were initiated after >24 h (65.2%), died (Chi-square =1.55, p=0.22). Conclusions: This study showed high mortality in infected patients with CRE infections and that the drug monotherapy and combination therapies were not effective in reducing patient mortality. Knowledge on risk factors associated with CRE infections could be useful for designing future treatment regimens to combat such infections and reduce mortality.