Risk Factors for Mortality in Patients with Stenotrophomonas maltophilia Bloodstream Infections in Immunocompetent Patients

Abstract

Objective: This study aimed to evaluate bloodstream infections caused by Stenotrophomonas maltophilia in immunocompetent patients with respect to clinical features and risk factors for mortality. Methods: We reviewed bloodstream infections detected between January 1, 2012, and July 1, 2021, to identify nosocomial S. maltophilia bacteremia in Koşuyolu Research and Training Hospital. Results: We identified a total of 97 patients with S. maltophilia bloodstream infections. Of these, 17 patients were excluded because of community-acquired infections (n=9), contamination with S. maltophilia (n=3), and insufficient data (n=5), with 80 (57.5% males) patients remaining for analysis. The source of infection was the respiratory tract in 28 (35%) patients. A central venous catheter was used in 60 (75%) patients, which required replacement in 23 patients within five days after detecting S. maltophilia bacteremia. On antimicrobial susceptibility testing, 71 strains were found to be susceptible and 9 (11.3%) resistant to trimethoprim-sulfamethoxazole. Thirty-day mortality was 33.8%. Non-survivors differed significantly from survivors with respect to higher rates of central venous catheters (p=0.020), mechanical ventilation (p=0.006), urinary catheters (p=0.021), septic shock (p=0.001), hypoalbuminemia (p=0.026) and thrombocytopenia (p=0.039). S. maltophilia bacteremia was independently associated with mortality in patients with hypoalbuminemia, and replacement of central venous catheters had a protective role in reducing mortality. Conclusion: As with other bacterial infections, S. maltophilia bacteremia is associated with a considerably high mortality rate in patients with cardiac conditions. The replacement of the catheter seems to play a beneficial role in 30-day survival.