Frequency of nosocomial infections as revealed by a prevalence survey.

In 1984, a prevalence survey based on the methodology, definitions and criteria meeting the WHO requirements was carried out in the Czech Socialist Republic. This prevalence study on a total of 12,260 hospital patients revealed 751 active cases of nosocomial infection (NI). The conclusions emerging from an epidemiological analysis of the collected NI patient records were as follows: 60% of all infections were acquired on the surgical services, predominantly on the surgery service; 60% of those who developed NI were persons over 50 years of age; hospital-associated infections afflicted 366 males and 385 females; the ratio of infections acquired prior to hospital presentation to those originating while in hospital care was about 4:1, with a tendency to vary depending on type of hospital service; the urinary tract was the most frequent site of infection (25%), followed by surgical wounds (15%) and upper respiratory tract (13%); 17% of NI patients contracted the infection in spite of preventive doses of antimicrobials, 28% of NI patients received no antimicrobial prophylaxis; among the 78% (589 out of 751) of patients examined bacteriologically, 46% of infections were caused by Gram-negative rods, 19% by staphylococci, 7% by streptococci and 6% by Pseudomonas aeruginosa; 22% of NI patients were not examined for the pathogen. The prevalence survey methodology turned out to be useful as a tool for detecting the immediate magnitude of the NI problem, but can also be used as a control method.