Alcaligenes xylosoxidans Bloodstream Infections in Outpatient Oncology Office

In 2002, we investigated a cluster of patients with Alcaligenes xylosoxidans bloodstream infections by conducting a matched case–control study and a prospective study. Pulsed-field gel electrophoresis (PFGE) was performed on blood culture isolates, and 1 explanted central venous catheter (CVC) was tested for biofilm. We identified 12 cases of A. xylosoxidans bloodstream infection. Case-patients were more likely than controls to have had a CVC (7/7 [100%] vs 4/47 [8.7%], respectively; p<0.0001). Ten case isolates were indistinguishable by PFGE analysis, and A. xylosoxidans biofilm from the CVC matched the outbreak strain. We observed multiple breaches in infection control, which may have caused contamination of multidose vials used to flush the CVCs. Our study links A. xylosoxidans with CVC biofilm and highlights areas for regulation and oversight in outpatient settings.