Transmission of a pathogen occurs via a contaminated intermediary. For example: C. difficile spores contaminate a HCW gloves. When removing her gloves, the provider unknowingly contaminates her hands. She practices immediate hand hygiene with an alcohol based hand rub (does not kill spores). She uses the electronic thermometer on the next patient, checks her vitals and straightens her pillow. The spores are on the thermometer handle, the patient and the linens. The HCW serves as the intermediary; the transporter.