Valutazione in campo dell'efficacia di disinfettanti utilizzati in alcuni ospedali

Among the various and complex aspects concerning the etiology of nosocomial infections, a rilevant role is played by the indiscriminate and incorrect use of disinfectants: they may change paradoxically from devices used for nosocomial infection prevention into carriers of infections. Critical situations are: a) inadequate cleaning of the container; b) inaccurate con centration set up; e) use of unsterilized water as a diluent; d) introduction of gauze or cotton flocks into the container; e) disinfectant contact with inactivating substances such as soaps, detergents, and organic substances; f) solution stability; etc. Therefore, in the light of the experience we acquired in the field of nosocomial infections, we believed interesting to carry out a study in order to detect contamination of disinfectants used in variuos hospitals in Naples as well as their usage. In the period from January to May 1988, 243 disinfecting solutions routinarely used is surgical departments of the 2nd School of Medicine and of three large neapolitan hospitals were tested for microbiological contamination. The analysis was carried out according to Kelsey and Maurer. 13 disinfectants were contaminated. The bacterial count exceeded the value of 5000 col/mi in 6 cases, while for the other disinfectants there were levels between 2500 and 4500 col/mi. 64% of the microorganisms isolated belonged to Pseudomonas spp. (cepacia, aeruginosa, fluorescens, maltophilia), while Acinetobacter calcoaceticus and Staphilococcus epidermidis were found in 21% and 15% of specimens respectively. A major consideration arising out from our study is the little attention payed to health problems related to disinfection by hospital staff, together with a lack of knowledge about the proper way of using disinfectants. Therefore it would be necessary to train the hospital staff in order to give them the essential background about disinfection and sterilization specifi-cally oriented to the main features of disinfectants and the factors eventually affecting their effectiveness (concentration, stability, contact time, temperature, pH, preliminary cleaning of the material, etc).