DISTRIBUTION OF BACTERIA ON HANDS AND THE EFFECTIVENESS OF BRIEF AND THOROUGH DECONTAMINATION PROCEDURES USING NONMEDICATED SOAP

Our perception of the role of hand washing in the clinical situation i s based on experimental studies in which test-bacteria are usually ino culated onto the skin surface and removed using hand washing preparati ons containing antiseptics. In this study, we have investigated the di stribution of bacteria on the hands of volunteers and the effectivenes s of long (3 minute) and brief(10 second) washes in removing both natu rally-occurring and artificially-inoculated bacteria (Micrococcus sp.) , using only soap and water. There was a tenfold reduction in median c ounts of artificially inoculated bacteria following both long and brie f washes. However, less than 50% of naturally-occurring bacteria were removed and, for hands previously disinfected by immersion in 70% etha nol, the washing procedure increased bacterial counts. In both unwashe d hands, and hands washed following a strict protocol, the mean variat ion in counts of naturally-occurring bacteria at different sites (wris ts, dorsal surface, palmar surface, fingertips and interdigital spaces ) was only two-fold. The efficiency of recovery of naturally-occurring organisms was estimated by repeated swabbing, to be more than 60%. Th e data question the value of typical hand wash procedures recommended by many authorities for use in clinical situations and of the perfunct ory hand washes frequently adopted by nursing staff in busy wards. Exp erimental evidence is required to justify procedures and to identify t he precise circumstances in which they are of value.