A urokinase-associated outbreak of Ralstonia mannitolilytica bloodstream infections in haemodialysis patients in north-eastern Italy, January to April 2023

An outbreak of Ralstonia mannitolilytica bloodstream infections occurred in four hospitals in northeastern Italy, involving 20 haemodialysis patients with tunnelled central vascular catheter access. We identified as the outbreak source a batch of urokinase vials imported from India contaminated with R. mannitolilytica. Whole genome sequences of the clinical and urokinase strains were highly related, and only urokinase-treated patients were reported with R. mannitolilytica infections (attack rate = 34%; 95% confidence interval: 22.1-47.4). Discontinuation of the contaminated urokinase terminated the outbreak.

Automated summary

An outbreak of Ralstonia mannitolilytica bloodstream infections occurred in northeastern Italy, involving 20 haemodialysis patients with tunnelled central vascular catheter access. The outbreak was traced back to a batch of urokinase vials imported from India contaminated with R. mannitolilytica. Whole genome sequencing confirmed the relationship between the clinical and urokinase strains, with only urokinase-treated patients reporting R. mannitolilytica infections (attack rate = 34%; 95% confidence interval: 22.1-47.4). Discontinuing the use of contaminated urokinase ended the outbreak.