Stenotrophomonas maltophilia Infections in Geriatric Patients

Roopa Anmolsingh,Dhyanesh Pandya,Don Walter Kannangara

doi:10.31487/j.ggr.2020.02.05

Abstract

We present Stenotrophomonas maltophilia infections in 317 hospitalized patients in a large health network over a 3-year period. The majority of patients were elderly. Most infections were polymicrobial: respiratory 95.2%, wound 91%, urinary 80.8% and blood 64.3%. Younger patients were small in number and were more common in those with otitis externa, infections from injection drug use and those with line infections. Most deaths were in patients with terminal conditions and polymicrobial infections and mortality could not be directly attributed to Stenotrophomonas maltophilia. None of the sputum, bronchial, urinary or wound culture positive patients had positive blood cultures. Only blood (14/317) or ear (7/317) culture positive patients had significant numbers of younger individuals with only 3 out of 14 over age 50 in blood culture positive patients and 1/7 in those with otitis externa. Those with bacteremia included patients with injection drug use, chronic pain syndromes and vascular catheter infections. 94% of urinary infections, 91.7% wound infections and 85.8% respiratory isolates were in those above age 50. Overwhelming majority of urinary infections were in males with drainage devices present in 75%. Recurrent infections were uncommon. Respiratory specimens were frequently associated with tracheostomies and endotracheal tubes. Most wound infections were in chronic lower extremity ulcers. Prior carbapenem use was not significant in this study. Isolates from all sites were over 98% susceptible to Trimethoprim/sulphamethoxazole. Limitations: The study group only had 1 organ transplant and 2 cystic fibrosis patients and no burn wound infections.

Highlights

Stenotrophomonas maltophilia is a gram-negative bacillus known for inherent resistance to antibiotics, biofilm formation, association with carbapenem use, cystic fibrosis, hospital-acquired infections, burn wounds and immunocompromised [1,2,3,4,5,6,7,8,9,10,11,12,13]
There was a clear association with Foley and suprapubic catheters, urinary stents, tracheostomies and endotracheal tubes
Our study shows that Stenotrophomonas maltophilia is predominantly found in elderly patients (Table 1) with the exception of bacteremia and ear infections

Summary

Introduction

Stenotrophomonas maltophilia is a gram-negative bacillus known for inherent resistance to antibiotics, biofilm formation, association with carbapenem use, cystic fibrosis, hospital-acquired infections, burn wounds and immunocompromised [1,2,3,4,5,6,7,8,9,10,11,12,13]. The attributable mortality was low in our study (Tables 3 & 4) in contrast to prior reports with rates as high as 37.5% [14, 15]. Such overestimates are probably due to inadequate attention given to polymicrobial infections and serious underlying conditions (Tables 5 & 6) that contributed to deaths that were not adequately assessed

Methods

Results

Discussion

Conclusion