[Outbreak of Raoultella ornithinolytica infection in patients cared at a hemodialysis center].

Objective: In July 2022, an outbreak of Raoultella ornithinolytica infection was detected in users of a hemodialysis center in Granada and central venous catheter (CVC) users. The aim of this study was to describe the development of the outbreak and the control measures implemented as well as to identify the risk factors that may have been related to its origin.

Methods: A study of a series of thirteen cases with positive blood culture for Raoultella ornithinolytica was conducted during July 2022. Two hypotheses were considered: direct transmission through contamination of the antiseptic product or cross-contamination through the hands of healthcare personnel. A descriptive data analysis was carried out, with the calculation of attack rates and attributable risk in the exposed group (CVC users).

Results: The center performed dialysis on 117 patients. 36 patients had a CVC, and 81 had an arteriovenous fistula (AVF). The total number of infected cases was 13. The attack rate was 11.1%, being 36.1% in patients with CVC and 0% in patients with AVF. The symptoms occurred between 1 and 3 hours after the start of dialysis, except in three cases that occurred after receiving dialysis in other centers. Samples of water, liquids and antiseptics were negative.

Conclusions: An outbreak of Raoultella ornithinolytica bacteraemia is confirmed, due to possible cross-contamination in the CVC handling and antisepsis process. Possibly, the germ was carried by a container of alcoholic chlorhexidine that contaminated the catheter and caused bacteremia during the hemodialysis process.