[Nosocomial infections in an urology department: temporal tendencies of the accumulated incidence during the period 1984-1988].

The yearly changes in the accumulated incidence (AI), localizations and responsible microorganisms of nosocomial infections (NI) which occurred over the period from 1984 to 1988 in the Urology Department of the Ramón y Cajal Hospital are described and a study of the seasonal tendency of such infections is carried out with data obtained from the Watch Out System by means of the annual AI rates to a ponderate regression curve. The yearly decrease in the risk of suffering a NI (expressed as the slope of the graph line) was 2.05% which was statistically significant. The most frequent localizations of NI were urinary, superficial postoperative wounds and bacteremia, representing the three of them almost 90% of the total number of infections each year. Urinary infection was the localization which presented the greatest annual decrease in risk (2.21%). Bacteremia also presented a decrease, although this was not significant. On the contrary, the risk of acquiring an infection in a superficial postoperative wound experimented during this period a significant annual increase (0.36%). E. coli, S. marcescens, and P. aeruginosa were the microorganisms most frequently isolated in NI.