Outbreak of bloodstream infections because of Serratia marcescens in a pediatric department

BackgroundSerratia marcescens can cause health care-associated infections. We herewith report the investigation and control of an outbreak of S marcescens bloodstream infections (BSI) in a general pediatric department.MethodsFrom April to May 2009, temporally related cases of S marcescens BSI occurred in a 40-bed general pediatric department of a tertiary care hospital. An outbreak investigation including case identification, review of medical records, environmental cultures, patients’ surveillance cultures, personnel hand cultures, pulsed-field gel electrophoresis, and a case-control study were conducted. Controls were patients without S marcescens BSI but hospitalized in the department for at least 48 hours during the outbreak. Enhanced infection control measures were immediately implemented by the Infection Control Committee.ResultsDuring the study period, 4 patients developed BSI because of a S marcescens strain demonstrating the same antimicrobial susceptibility pattern as well as the same molecular profile. Patients’ surveillance cultures and personnel hand cultures were negative. In 1 case-patient, S marcescens grew from cultures of intravenous infusion systems. In the case-control study performed, there were no differences in demographics, intravenously administered medications, or place of hospital stay. Case patients had changes in vascular access significantly more frequently than controls. No S marcescens infections occurred in the department during the 18 months following implementation of the enhanced infection control measures.ConclusionPrompt recognition and strict adherence to infection control measures are of paramount importance in combating an outbreak of S marcescens bloodstream infection.