PubMed1996
According to the field of application, strategies for the prevention of the transfer of microbial skin flora from the hands must consider the various categories of flora: transient, resident or stemming from infected lesions on the hands (infection flora). Depending on the species and virulence of the microorganism and of the susceptibility of the infection target, transient flora may or may not be of pathogenic importance. In contrast, resident skin flora is usually regarded as pathogenic only under certain circumstances such as in surgery, especially with transplantation of foreign bodies and in highly susceptible hosts. Microorganisms stemming from infected lesions are of proven pathogenicity. In the non-surgical field, only the transient and infection flora from the hands play a role. Such lesions are an absolute contraindication for patient-care, preparation of pharmaceuticals or foodstuff. In some procedures, the transmission of transient flora can be prevented by use of the non-touch technique ("instruments instead of fingers") or by the intelligent use of protective gloves. Hands already contaminated may be rendered safe by procedures for the elimination of transients such as handwashing, hygienic handwash and hygienic hand rub (in the order of increasing efficacy). Among all useable chemicals, ethanol, isopropanol and n-propanol (in the order of increasing efficacy) are the strongest and fastest agents. Furthermore, the duration of treatment (between 30 and 60 s) significantly influences the achievable reduction of microbial release. According to the new European standards (CEN) for testing chemical disinfectants and antiseptics, products for hygienic handwash must be significantly more efficacious than unmedicated soap, on artificially contaminated hands. In contrast, products for the hygienic hand rub must not be significantly less efficacious than a reference disinfection including isopropanol 60% vol rubbed onto the hands of the same volunteers during 1 min. By this, the average reduction of microbial release amounts to 4.2 to 4.4 lg, in our hands. The effectiveness of procedures for the hygienic handwash is usually significantly lower than that of alcoholic rubs. Therefore, in hospitals, they can be used only in certain indications such as patient care in reverse isolation, preparation of pharmaceuticals or foodstuff. In the surgical field, where not only transient but also resident flora is a cause of post-operative infection, the microbial release from the hands of the surgical team into the surgical wound must be prevented by using surgical gloves. Because of frequent glove lesions, a surgical hand disinfection is usually performed before donning gloves to keep a possible inoculumn as small as possible. Also in this field of application, alcoholic rubs proved to be significantly more effective than washing hands with antiseptic detergents. There exists a strong positive correlation of the reduction of microbial release and the duration of hand treatment, between 1 and 5 min. The European test standards (CEN) require products for surgical hand disinfection to be at least as efficacious as a reference disinfection of clean hands, which are constantly rubbed and kept wet with n-propanol 60% vol during 3 min. By this, the achievable average reduction of the microbial release ranges between 2.0 and 2.4 lg. In contrast, antiseptic washing procedures with preparations containing povidone-iodine, chlorhexidine gluconate or triclosan reduce the bacterial release within 2-5 min only by 0.5 to 1.2 lg. Some of them exert a bacteriostatic sustaining effect which is not found with alcoholic preparations. This, however, is not necessary with the latter as the initial bacterial reduction is that strong that restitution of the skin flora takes > 3 hours. Alcoholic preparations are at least as tolerable for the skin as antiseptic detergents, if not better, if they contain suitable emollients. Because dilution renders alcohols i