Bacterial contamination of the hands of hospital staff during routine patient care

Background: Cross-transmission of microorganisms by the hands of health car e workers is considered the main route of spread of nosocomial infections. Objective: To study the process of bacterial contamination of health care w orkers' hands during routine patient care in a large teaching hospital. Methods: Structured observations of 417 episodes of care were conducted by trained external observers (S.T. and V.S.). Each observation period started after a hand-cleansing procedure and ended when the health care worker pro ceeded to clean his or her hands or at the end of a coherent episode of car e. At the end of each period of observation, an imprint of the 5 fingertips of the dominant hand was taken and bacterial colony counts were quantified . Regression methods were used to model the intensity of bacterial contamin ation as a function of method of hand cleansing, use of gloves during patie nt care, duration and type of care, and hospital ward. Results Bacterial contamination increased linearly with time on ungloved ha nds during patient care (average, 16 colony-forming units [CFUs] per minute ; 95% confidence interval, 11-21 CFUs per minute). Patient care activities independently (P<.05 for all) associated with higher contamination levels w ere direct patient contact, respiratory care, handling of body fluid secret ions, and rupture in the sequence of patient care. Contamination levels var ied with hospital location; the medical rehabilitation ward had higher leve ls (49 CFUs; P = .03) than did other wards. Finally, simple hand washing be fore patient care, without hand antisepsis, was also associated with higher colony counts (52 CFUs; P = .03). Conclusions: The duration and type of patient care affect hand contaminatio n. Furthermore, because hand antisepsis was superior to hand washing, inter vention trials should explore the role of systematic hand antisepsis as a c ornerstone of infection control to reduce cross-transmission in hospitals.