Zbl. Bakt. 285, 565-575 (1997) © Gustav Fischer Verlag, Jena Distribution of Bacteria on Hands and the Effectiveness of Brief and Thorough Decontamination Procedures Using Non-medicated Soap ANGELA N. CHAMBERLAINl, MAHMOUD A. HALABLAB2, DINAH ]. GOULD l , and ROGER ]. MILES 2 1 Department of Nursing Studies and 2 Division of Life Sciences, King's College, Cornwall House, London SEl 8WA, UK Received March 25, 1996 . Accepted July 19, 1996 Summary Our perception of the role of hand washing in the clinical situation is based on experi mental studies in which test-bacteria are usually inoculated onto the skin surface and re moved using hand washing preparations containing antiseptics. In this study, we have in vestigated the distribution of bacteria on the hands of volunteers and the effectiveness of long (3 minute) and brief (10 second) washes in removing both naturally-occurring and arti ficially-inoculated bacteria (Micrococcus sp.), using only soap and water. There was a ten fold reduction in median counts of artificially inoculated bacteria following both long and brief washes. However, less than 50% of naturally-occurring bacteria were removed and, for hands previously disinfected by immersion in 70% ethanol, the washing procedure in creased bacterial counts. In both unwashed hands, and hands washed following a strict pro tocol, the mean variation in counts of naturally-occurring bacteria at different sites (wrists, dorsal surface, palmar surface, fingertips and interdigital spaces) was only two-fold. The ef ficiency of recovery of naturally-occurring organisms was estimated by repeated swabbing, to be more than 60%. The data question the value of typical hand wash procedures recom mended by many authorities for use in clinical situations and of the perfunctory hand wash es frequently adopted by nursing staff in busy wards. Experimental evidence is required to justify procedures and to identify the precise circumstances in which they are of value. Introduction Hand decontamination is perceived as fundamental to infection control in hospital wards (Reybrouck 1983). There is ample evidence that effective skin-decontamination may be achieved using antiseptic agents, such as iso-propanol (70% v/v) and 4% chi or hexidene gluconate solution for 10-30 seconds (Ayliffe et al. 1988, Lilly and Lowbury 1978, Larson et al. 1986). However, in routine nursing practice, antiseptic agents are frequently not available (Gould 1995) and, even where present, are often not employed (Gould 1994). This reflects both cost and skin-damage incurred through frequent use