Objective.To evaluate the impact of an infection control program in an intensive care unit (ICU).

Design.Prospective before‐after study. Two 6‐month study periods were compared; between these periods, an infection control program based on isolation was implemented.

Setting.Polyvalent ICU of Montpellier Teaching Hospital.

Patients.Any patient who was hospitalized in the ICU for >48 hours and was discharged during 1 of the 2 periods.

Main Outcome Measures.The main patient‐related variables were sex, age at admission, type of patient (surgical, medical, or trauma), Simplified Acute Physiology Score II, length of ICU stay, need for intubation, duration of exposure to invasive devices, onset of nosocomial infection and pathogens responsible, and death. We compared the 2 study periods with respect to the incidence of 4 nosocomial infections (pneumonia, urinary tract infection, bacteremia, and catheter‐associated infection), the frequency of infection with the main multidrug‐resistant pathogens, and patient survival.

Results.Patients in periods 1 and 2 were similar with regard to sex, age, physiology score, and exposure to invasive devices. The rates of infection with multidrug‐resistant pathogens were significantly lower during period 2 than during period 1 (infection rate: 28.1% of patients in period 1 and 9.6% of patients in period 2 [ ]; pneumonia rate: 32.6% of patients in period 1 and 4.2% of patients in period 2 [ ]). The mortality rate among patients with nosocomial pneumonia was 38.2% in period 1 and 4.3% in period 2 ( ).

Conclusions.After implementation of an infection control program, the rate of infection with multidrug‐resistant pathogens decreased, as did the mortality rate among patients with nosocomial pneumonia.