Serratia marcescens transmission in a pediatric intensive care unit: A multifactorial occurrence

Background: Fourteen patients in the pediatric cardiac intensive care unit (CICU) had ≥1 positive culture for a single strain of Serratia marcescens from April through December 1995 (study period). Objectives: To identify risk factors for S marcescens infection or colonization in a pediatric CICU. Methods: Retrospective case-control study. Assessment of CICU infection control practices and patient exposure to CICU health care workers (HCWs). Epidemiologic-directed cultures of the environment and HCWs’ hands were obtained. Setting: Pediatric CICU. Patients: Fourteen patients in the pediatric CICU had ≥1 positive culture for a single strain of S marcescens from April through December 1995 (study period). CICU patients who did not have S marcescens infection or colonization during the study period were randomly selected as controls. Results: A case patient was more likely than a noncase patient to have exposure to a single HCW (odds ratio [OR], 19.5; 95% CI, 2.6-416; P