Prevalence of hospital-associated infections in five Swedish hospitals in November 1975.

The prevalence rate of hospital-associated infections in 5 Swedish hospitals on November 4, 1975 is reported. In all, 4246 patients were included in the study, 3657 in acute disease clinics and 589 in chronic disease clinics. The overall prevalence rate was 17%, 11% in acute disease clinics and 59% in chronic disease clinics. The highest rate was found in intensive care units (72%), while in ophthalmological units it was 1%. 50% of all hospital-associated infections were urinary tract infections, 68% of which occurred in patients with an indwelling urinary catheter. 25% of all infections in acute disease clinics were postoperative wound infections, and 20% in chronic disease clinics were skin infections, including infections in varicose and decubital ulcers. 58% of the bacterial isolates from hospital-associated infections were gram-negative rods, while 12% were Staphylococcus aureus. Also in postoperative wound infections the gram-negative rods dominated over Staph. aureus, 35 vs. 23%. A prevalence study of this order of size seems adequate to assess the overall rate of hospital-associated infections in Sweden as compared to other countries. However, differences in prevalence rates between hospitals and clinics should be interpreted with great care. The seriousness and effect of reported infections must be evaluated otherwise, as well as the day-to-day infection control and the evaluation of prophylactic measures need other methods.