716 Increased Mortality in Burn Center Admissions with Stenotrophomonas Maltophilia

Abstract Introduction Stenotrophomonas maltophilia (SM) is a non-fermenting, gram-negative bacterium that is a challenge to treat in immunocompromised hosts. It is difficult to eradicate due to its natural resistance to multiple antibiotics and omni-presence. Our objective was to evaluate the clinical characteristics of burn patients diagnosed with SM infection in our Burn Unit. Methods A single-site, retrospective review using an institutional Burn Center registry and infection control data. All patients diagnosed with SM infection within our Burn Unit between June 1, 2012 and June 1, 2019 were included in this retrospective review. Demographics, burn characteristics, length of stay and mortality were evaluated. Patients were then compared to all admitted patients who were ventilated for greater than 4 days during the same time period. Significance was accepted at p< 0.05. Results Forty-seven patients were diagnosed with SM infection between 2012 to 2019. Among these patients 64% were male and 36% were female. Mean patient age was 51 years old +/- 16 years. The most common reason for admission was flame burns (64%), followed by Stevens Johnson/Toxic Epidermal Necrolysis (SJS/TEN) (17%). The average total body surface area (TBSA) involved was 29% +/- 18%. Mean time from admission to a positive SM culture was 34.5 days. One-hundred percent of the patients were intubated. Positive cultures for SM were obtained from bronchial alveolar lavage in 96% of positive cultures for SM. Mean length of stay in this group was 108 days +/- 86 days, ranging from 5 to 362 days. The mortality rate for patients diagnosed with a SM infection was 40%, compared to 27% in all patients admitted during this time who were ventilated for greater than 4 days. Conclusions SM is a highly virulent bacteria associated with increased morbidity and mortality in patients admitted to our burn unit. The patients with positive cultures were older, male, flame injured, mechanically ventilated, had large TBSA involvement, and had prolonged hospital courses. Applicability of Research to Practice This study demonstrates the virulence of SM in a high-volume burn center. Cultures positive for SM require aggressive source control and burn centers need to be hypervigilant in controlling environmental factors to mitigate risk.