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.

Emergence of Stenotrophomonas maltophilia nosocomial isolates in a Saudi children’s hospital

“…In contrast, Sattler et al17 found that prematurity, primary immunodeficiency, and congenital heart disease were unique and more common risk factors among pediatric patients in their study. In contrast with many previous studies, exposure to antibiotics in this study was found in both infected and colonized patients 13,14,22,26. Carbapenems are among the classes of antibiotics most frequently associated with S. maltophilia isolation 26.…”

“…Respiratory tract infection, especially VAP, and BSI are the most common infections reported in many clinical and epidemiological studies. The spectrum of the clinical diseases caused by S. maltophilia in this study was similar to that observed in other relevant studies 3,5,11-13…”

“…In this study, the predisposing factors associated with S. maltophilia infection were similar to those reported by other studies that primarily described S. maltophilia isolations among adult patients 5,11,13,14,16,25. These risk factors included prolonged hospitalization, presence of a CVC, neutropenia, ICU admission, mechanical ventilation, or tracheotomy, prior antibiotic therapy, and underlying disease.…”

“…Its isolation from the respiratory tract has been frequently interpreted as colonization rather than as infection 8,9. Many previous studies have found a large proportion of colonizing S. maltophilia isolates, with rates of true infection of 13-71% 13-15,22,23. In this study, 75% of the 64 isolates were identified as true infections.…”

“…Trends of increasing resistance to these individual antimicrobials have been recently reported in many clinical studies and combined therapeutic regimens are recommended 11,12. Most clinical and epidemiological studies of S. maltophilia have focused on the adult population,5,8,11,13,14 and only a few reports have described nosocomial infections in pediatric patients 12,15-17. Moreover, the national data on the antimicrobial susceptibility of S. maltophilia in Saudi Arabia is limited.…”