Spread of Staphylococcus aureus between medical staff and high-frequency contact surfaces in a large metropolitan hospital

Objective: To examine whether bacteria are transferred between the hands of medical staff and high-frequency contact surfaces within and between departments of a major metropolitan hospital, and to further analyze the patterns of cross-transmission. Methods: Microbiological samples were collected from the hands of 112 hospital employees as well as from 120 high-frequency contact surfaces in four hospital departments. Samples were collected on agar plates, analyzed for the presence of Staphylococcus aureus or methicillin-resistant S. aureus (MRSA) by standard microbiology testing, and partially genotyped using pulsed-field gel electrophoresis. Results: Genetically identical MRSA was identified on the surface of an electrocardiography device in the medical intensive care unit and on the same type of device in the neurosurgical unit. Genetically similar S. aureus was identified on an infusion pump in the medical intensive care unit and on the hands of several doctors in a different department who regularly use that pump. Genetically identical S. aureus was also identified on bedside rail restraint in the medical intensive care unit and on the hands of the nurse in the neurosurgical unit. Finally, genetically similar MRSA was identified both on the surface of an electrocardiography device and on the suction apparatus in the medical intensive care unit. Conclusion: Cross-contamination of S. aureus or MRSA on medical workers' hands and contact surfaces was demonstrated within and between departments of a large metropolitan hospital. Improvements are needed in medical staff hygiene habits and in the cleaning of high-frequency contact surfaces to help prevent and control nosocomial infections