Epidemiologic aspects of nosocomial infections

In a currently ongoing surveillance of hospital-associated infections in two metropolitan hospitals in Oklahoma, the results over a four-month period suggest at least tentative principles of host-agent relationships in hospital-associated infections. Within the urinary tract, the site with the highest number of total isolations, Escherichia coli and Klebsiella pneumoniae were the most common pathogens. By age, the under 5 and over 60 year age groups had the highest number of isolations. Staphylococcus aureus and E coli were isolated more frequently in the younger group, while K pneumoniae, Serratia marcescens, and Proteus mirabilis occurred more frequently in infections among the older group. A higher frequency of Enterobacter sp and S aureus were isolated among male patients, while Candida albicans and E coli apparently had a greater affinity for females; however, none of these differences by sex were statistically significant. Over 50% of the infections were manifest within the first ten days of hospitalization.