A multi-center outbreak of Candida tropicalis bloodstream infections associated with contaminated hemodialysis machine prime buckets

•Candida species seldom cause hemodialysis-related bloodstream infections (BSIs).•An outbreak of C. tropicalis BSIs affected 3 hemodialysis units located in 2 cities.•Inadequate saline prime bucket disinfection was the primary cause of the outbreak.•Continued emphasis on saline prime bucket disinfection is warranted. Outbreaks of fungal bloodstream infection (BSI) are uncommon among hemodialysis patients. We investigated an outbreak of Candida tropicalis BSIs involving patients at 3 of 4 affiliated hemodialysis units. An investigation included a review of records of patients with C tropicalis BSI, a case-control study, and cultures of medications, hands of personnel, dialysis equipment, and water samples. Eight patients developed C tropicalis BSIs in a 3-month period. Compared to controls, cases had a higher proportion of preceding dialyses performed on a machine with a contaminated saline prime bucket (SPB) (P= .02). Observations revealed that SPBs at units A-C were rinsed with tap water, were not routinely disinfected, and that priming tubing was allowed to contact fluid in SPBs. C tropicalis was recovered from the main compartment and hollow handle of SPBs and from other environmental samples. C tropicalis isolates from patients, SPBs and other environmental samples had indistinguishable pulsed-field gel electrophoresis patterns. Following routine disinfection of SPBs, the outbreak terminated. This outbreak was likely due to inadequate disinfection of SPBs. The findings emphasize the importance of disinfection of SPBs. Current use of identical SPBs warrants further evaluation of hollow SPB handles as a potential infection risk.