The epidemiology of multidrug-resistant bacteria colonization and analysis of its risk factors in intensive care unit

Abstract

To screen the colonization of multidrug resistant organisms ( MDROs ) and determine their risk factors in intensive care unit ( ICU ), so as to provide the basis of prophylaxis and treatment of MDROs colonization. A prospective single-center study was conducted in ICU of China-Japan Friendship Hospital from June 2008 to December 2014. The nostril and anal swabs for each patient who stayed in ICU over 24 hours were collected. Each specimen was cultured and tested for drug sensitivity. Clinical findings and relative risk factors were collected. The risk factors of MDROs colonization were analyzed with univariate analysis. The independent risk factor was selected from the risk factors with P < 0.05 with logistic regression analysis to analyze the related factors of MDROs colonization in ICU. 1 672 patients were enrolled. At ICU admission, MDROs colonization was present in 604 cases ( 36.12% ), of whom 62 cases ( 3.71% ) were found to be colonized with methicillin-resistant Staphylococcus aureus ( MRSA ), 529 ( 31.64% ) were colonized with extended-spectrum β-lactamase ( ESBL ) enterobacteria, 7 ( 0.42% ) were colonized with multidrug resistant Acinetobacter baumannii ( MDR-AB ), and 6 ( 0.36% ) were colonized with multidrug resistant Pseudomonas aeruginosa ( MDR-PA ). ICU acquired MDROs colonization were 197/1 068 ( 18.45% ), among whom 24 patients ( 1.44% ) were colonized with MRSA, 118 ( 7.06% ) were colonized with ESBL enterobacteria, 50 ( 2.99% ) were colonized with MDR-AB, and 5 ( 0.30% ) were colonized with MDR-PA. By multivariable analysis, prior administration of more than two kinds of antibiotics [ odds ratio ( OR ) = 2.352, 95% confidence interval ( 95%CI )= 1.847 - 4.464, P = 0.002 ], prior use of broad spectrum antibiotics within 3 months ( OR = 2.862, 95%CI = 1.458-5.631, P = 0.014 ), duration of prior antibiotic administration ( OR = 1.781, 95%CI = 1.152 - 3.413, P = 0.003 ) and hospitalization days prior to ICU admission > 9 days ( OR = 1.766, 95%CI = 1.235 - 3.986, P = 0.021 ) were independent risk factors of MDROs colonization on admission to ICU. High prevalence of MDROs colonization in ICU patients was found in our hospital, and ESBL enterobacteria was the predominant bacteria. ICU acquired MDROs colonization is also worth considering, especially for MDR-AB. Identification of risk factors for MDROs colonization may help identify and screen patients with high risk, and it is also instructive in prophylaxis of MDROs colonization/infection and restriction of the use of broad spectrum antibiotics.