Background: Nosocomial infections (NI) make up an important problem in Public Health Care. From an etiologic point of view they are characterized by their constant evolution over time. Thus, the aim of this study was to know the etiologic variations of NI in the surgery departments of a university hospital.
Material and methods: Active surveillance of NI in the departments of general, vascular and urologic surgery was undertaken in 1988 and 1996. The frequency of the presentation of different microorganisms was globally calculated and based on the localization of the infection.
Results: At present, the most important microorganisms were E. coli (20.6%), Enterococcus sp. (15.6%), S. epidermidis (8.8%), Streptococcus sp. (8.5%), other negative coagulase staphylococci (NCS) (5.7%), Pseudomonas sp. (5.5%), S. aureus (5.2%), and Candida sp. (4.3%). On analysis of the temporal evolution an increase was observed in gram positives (27.4% in 1988 and 46.4% in 1996). Enterococcus sp. increased in surgical infections (5.8% in 1988 and 15.8% in 1996) and in the urinary tract (8.5% in 1988 and 25.6% in 1996). Contrary to the S. epidermidis, the NCS increased in importance mainly in infections at the site of surgery (0% in 1988 to 5.1% in 1996). The appearance of Klebsiella sp., Enterobacter sp. and Proteus sp. decreased.
Conclusions: A great variation was observed in the etiology of nosocomial infections in surgery departments not only over time but also based on the localization of the infection. In recent years gram positive infections have increased with a rise in the incidence of staphylococci, streptococci and enterococci, in addition to greater protagonism by Candida sp.