Healthcare workers' hands represent the principal route of transmission of nosocomial pathogens. They are colonized permanently by the physiological flora ("resident flora") and temporarily, depending on the precise nature of the employee's duties, by various pathogens that do not belong to the physiological flora. Staphylococcus aurous , for example, can survive for over 2 h on the hands and is found in 10% to 78% of staff.