Stenotrophomonas maltophilia bacteraemia: 61 cases in a tertiary hospital in Denmark

Background Stenotrophomonas maltophilia is an opportunistic pathogen and a dreaded cause of bacteraemia with 30-day mortality rates ranging from 14 to 69%. The purpose of this cohort study was to evaluate outcomes of S. maltophilia bacteraemia, at Rigshospitalet, a tertiary hospital in Copenhagen, Denmark. Methods We included all patients with a blood culture positive for S. maltophilia, from January 1, 2015 to April 1, 2020. We extracted data on antimicrobial susceptibility, treatment, central venous catheter intervention and severe haematological disease. Results Sixty-one cases of S. maltophilia bacteraemia were identified. The overall 90-day mortality was 18%. Sixty percent of patients had a central venous catheter intervention performed. Seventy-nine percent of patients were treated with trimethoprim/sulfamethoxazole (TMP/SMX). Patients with central venous catheter intervention had significantly better survival than those without (HR: 0.16 [95% CI: 0.03-0.73]). Severe haematological disease and patients, who received intensive care unit (ICU) care, were at higher risk of death than other patients (HR: 5.93 [95% CI: 1.18 - 29.94] and HR: 8.37 [95% CI: 1.79 - 39.20], respectively). We found no evidence that any antibiotic regime was superior with regard to 90-day mortality. Conclusions We did not find evidence to support a change in the current standard-of-care regimen of TMP/SMX and CVC removal. Larger clinical trials are needed to guide such recommendations.