Background: We compared the relative frequency of pathogens isolated from 1985 to 1989 (N = 4358) with those isolated from 1980 to 1984 (N = 5290) in a university hospital to determine trends in the relative importance of pathogens causing nosocomial infection.
Methods: Our study was based on surveillance data prospectively obtained between 1980 and 1989 from a 600-bed university hospital. Statistically significant trends occurring from 1980 to 1984 to 1985 to 1989 were determined by chi 2 tests with Bonferroni corrections (i.e., p less than [0.05/17]).
Results: Overall an increased frequency of isolation occurred for Candida and other yeasts and for Haemophilus species. A decreased frequency was noted for Proteus species, non-Bacteroides anaerobes, and Serratia species. Comparison of 1985 to 1989 with 1980 to 1984 revealed that the most significant change in nosocomial pathogens was the marked increase in infections with yeast, principally Candida species. Candida and other yeast infections increased 40%, from 7.6% (rank, 5) to 10.6% (rank, 3) of all pathogens isolated. Increases, which occurred in urine, blood, and wound isolates, were especially marked among surgical patients. In addition, a significant increase was noted among blood isolates in the isolation of yeast other than Candida albicans.
Conclusions: We conclude that Candida and other yeasts are being isolated increasingly as causative agents of nosocomial infection.