MODELING THE SPREAD OF RESISTANT NOSOCOMIAL, PATHOGENS IN AN INTENSIVE-CARE UNIT

OBJECTIVES: To show the value of mathematical modeling in simulating t he spread of nosocomial pathogens in an intensive-care unit (ICU), to provide a framework for listing available knowledge; to predict the be nefits of various control measures; and to supplement the epidemiologi cal assessment of these measures. DESIGN: Simulated outbreak of a noso comial pathogen in an ICU, based on a deterministic compartmental mode l describing both person-to-person spread and indirect spread between patients through staff members. INTERVENTIONS: Simulation of three typ ical colonization control measures: effective handwashing compliance a mong staff members, ICU antimicrobial policy, and curtailing ICU admis sion of colonized patients. RESULTS: In controlling colonization, effe ctive handwashing compliance reduced staff member colonization, but on ly moderately limited patient colonization unless the ICU was isolated strictly by curtailing the admission of colonized patients. The impac t of antibiotic policy was very slight. CONCLUSIONS: In the field of n osocomial infection, mathematical modeling appears to be a valuable to ol that can be used to evaluate the magnitude of the expected effects of control strategies and to guide the selection of the best randomize d clinical trials to pursue.