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

Background: Nosocomial outbreaks of Pseudomonas aeruginosa in pediatric hospitals frequently involve neonates and immunosuppressed patients and can cause significant morbidity and mortality.

Objective: To describe the investigation of a multidrug-resistant P. aeruginosa outbreak in a pediatric oncology ward at the Royal Children's Hospital, Melbourne, Australia.

Design And Methods: 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.

Results: 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.

Conclusion: 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.