Investigations on Epidemiology and Prophylaxis of Nosocomial Infections in Intensive Care Units

In the past decade gram-negative bacteria have been the main cause of hospital infections. It is assumed that this is associated with intensive administration of broad-spectrum antibiotics, with use of disinfectants mainly in the quaternary ammonium compounds group, and with the specific biological properties of gram-negative bacteria, such as minimal nutritional requirements and first-class adaptation to life in these disadvantageous environmental conditions [13–15, 17]. Especially difficult epidemiological and therapeutic problems are posed by infections evoked by antibiotic-resistant gram-negative bacteria in intensive care units (ICU). Patients in these units are particularly susceptible to infections. This is the consequence of the weakening of natural resistance mechanisms during serious illness and trauma, as well as of the administration of large doses of drugs, many of which are immunosuppressive. Treatment in the ICU calls for numerous methods, such as prolonged intravenous infusions, catheterization of the bladder, mechanical respiration, and aspiration of the bronchial tree secretion, which all add to the risk of infection by hospital strains [3, 8, 9, 11, 16].