Answer:
Transmission of health care-associated pathogens from one patient to another via HCWs’ hands requires five sequential steps (Figures I.7.1–6): (i) organisms are present on the patient’s skin, or have been shed onto inanimate objects immediately surrounding the patient; (ii) organisms must be transferred to the hands of HCWs; (iii) organisms must be capable of surviving for at least several minutes on HCWs’ hands; (iv) handwashing or hand antisepsis by the HCW must be inadequate or entirely omitted, or the agent used for hand hygiene inappropriate; and (v) the contaminated hand or hands of the caregiver must come into direct contact with another patient or with an inanimate object that will come into direct contact with the patient. Evidence supporting each of these elements is given below.
