Clinical characteristics and risk factors of infections caused by Stenotrophomonas maltophilia in a hospital in northwest China

Abstract

Introduction: Stenotrophomonas maltophilia infections have recently increased in importance in China, particularly in intensive care units (ICUs). The aim of this study was to investigate the clinical characteristics and risk factors of S. maltophilia infection in ICU of a hospital in northwest China.

Methodology: The characteristics and outcomes of patients with any type of S. maltophilia infection at Shaanxi Provincial People’s Hospital, Shaanxi, China, over a two-year period (from July 2011 to June 2013) were studied. S. maltophilia antimicrobial susceptibility was tested with the agar dilution method. The risk factors for all-cause in-hospital mortality were assessed with multivariate logistic regression.

Results: Forty patients (median age, 72 years; 77.5% males) with S. maltophilia infection were identified. The main type of infection was lower respiratory tract infection (97.5%); one patient had a bloodstream infection. A total of 97.5% patients were infected with two or more organisms at the same time. The main characteristics of the patients were prolonged use of mechanical ventilation, urethral catheter, and central venous catheter before the infections occurred. The case number of infection was not different in the four seasons. High in vitro sensitivity was observed to minocycline (91.2%), levofloxacin (85.3%), and trimethoprim-sulfamethoxazole (79.4%). Most patients received therapy with a combination of agents. The crude mortality was 50%. By multivariate analysis, low albumin content and hypotension were the independent prognostic factors for mortality.

Conclusions: Appropriate antimicrobial treatment had no positive impact on mortality. The impacts of  albumin supplements and increasing blood pressure on mortality require further clinical studies.