Comparison of two methods for assessing the removal of total organisms and pathogens from the skin

A standard hand-wash sampling technique was compared with a simple finger-streak sampling method in assessing the relative effectiveness of a number of alternative preparations used for disinfecting the surgeon's hands (alcoholic 0.5% chlorhexidine, alcoholic 0.1% tetrabrom-o-methyl phenol, a 4% chlorhexidine detergent solution, aqueous 0.5% chlorhexidine, 2% 'Irgasan' detergent solution and, as control, bar soap). There was a fairly good correlation between the results of assessment by the two methods after a single disinfection and after six disinfections, three on one day and three on the next. Significant differences were shown in 21 comparisons between treatments when the hand-wash sampling test was used, and 16 of these comparisons also showed a significant difference by the finger-streak test. Staphylococcus aureus was found in hand samplings from 5 out of 8 nurses in the Burns Unit of Birmingham Accident Hospital by the hand-wash sampling method and from 2 of the same 8 nurses by the finger-streak method; the numbers were small, and no Staph. aureus were isolated from the same hands after 1 min. wash in 70% ethyl alcohol. Similar sampling on 29 nurses in other wards showed Staph. aureus on 3 nurses (one in large numbers) by the hand-wash technique and on 1 nurse by the finger-streak test; in only 1 nurse whose hands showed Staph. aureus before disinfection was the organism found, by hand-wash sampling, after disinfection. Parallel sampling of nurses' hands after washing with soap and water and after disinfection with 95% ethanol showed larger numbers of Staph. aureus in a hospital for skin diseases than in a general hospital, and a lower incidence and somewhat lower density of Staph. aureus after ethanol treatment than after washing with soap and water; Gram-negative bacilli, on the other hand, were commoner on hands in the general than in the skin hospital, and present in much smaller numbers after disinfection with ethanol than after washing with soap and water. Antibiotic sensitivity tests showed the frequent recurrence on the hands of some nurses of multi-resistant Staph. aureus with resistance patterns similar to those found in infective lesions in some of the patients; different sensitivity patterns were usually found in staphylococci isolated from the nose. Even in wards where many patients were infected, carriage by nurses' hands of a particular strain of Staph. aureus did not seem to last for more than a few days.