To Örebro University

This study describe a large nosocomial outbreak of Clostridioides difficile infections (CDI) dominated by ribotype (RT) 046 in a Swedish hospital. The aim of the present study was to examine the pathogenicity of this RT, explore epidemiological links by whole genome sequencing (WGS) and evaluate different interventions implemented to stop the outbreak. Clinical isolates (n= 366) collected during and after the outbreak were ribotyped and 246 isolates were subjected to WGS. Medical records of patients infected with the seven most common RTs were evaluated. RT046 was spread effectively throughout the hospital and was the most common among the 44 different RTs found (114/366 isolates). Infection with RT046 was associated with higher mortality compared to other strains (20.2% to 7.8%), although there were no differences in concomitant disease, age or antibiotic treatment. In order to control the outbreak, a number of measures were successfully implemented.