Multiresistant Pseudomonas aeruginosa outbreak in a pediatric oncology ward related to bath toys

Abstract

Nosocomial outbreaks of Pseudomonas aeruginosa in pediatric hospitals frequently involve neonates and immunosuppressed patients and can cause significant morbidity and mortality. To describe the investigation of a multidrug-resistant P. aeruginosa outbreak in a pediatric oncology ward at the Royal Children's Hospital, Melbourne, Australia. Specimens were collected from infected patients and the ward environment. Bacterial isolates were characterized by antibiotic susceptibility patterns and bacterial DNA fingerprinting performed by pulsed-field gel electrophoresis (PFGE). A case-control study was carried out to assess possible risk factors for infection. Eight patients had clinical illnesses including bacteremia (n = 5) and infections of skin (n = 2), central venous catheter site (n = 1) and urinary tract (n = 1). The environmental ward survey yielded isolates of multiresistant P. aeruginosa from a toy box containing water-retaining bath toys, as well as from three of these toys. Pulsed-field gel electrophoresis of bacterial DNA demonstrated identical band patterns of the isolates from patients, toys and toy box water. A case-control study involving the 8 cases and 24 disease-matched controls demonstrated a significant association between P. aeruginosa infection and use of bath toys (P = 0.004), use of bubble bath (P = 0.014), duration of stay (P = 0.007) and previous antibiotic exposure (P = 0.026). Cultures from the bubble bath liquid were negative. This is the first description of a nosocomial outbreak associated with toys. We caution against the use of water-retaining bath toys in wards treating immunocompromised children.