Detection and Treatment of Antibiotic-resistant Bacterial Carriage in a Surgical Intensive Care Unit: a 6-year Prospective Survey

Objective: To describe, during a 6-year period, multidrug-resistant bacterial carriage in an intensive care unit (ICU).

Design: Prospective survey of 2235 ICU patients with methicillin-resistant Staphylococcus aureus (MRSA) and extended-spectrum beta-lactamase-producing Enterobacteriaceae (ESBL-E).

Setting: A surgical ICU in a tertiary-care teaching hospital.

Patients: All admitted patients.

Interventions: Nasal and rectal swabs were performed at admission and weekly thereafter. There was nasal application of mupirocin for MRSA carriers and selective digestive decontamination with local antibiotics for ESBL-E carriers.

Results: The swab compliance rate was 82% at admission and 51% during ICU stay. The rates of MRSA carriage or infection were 4.2 new cases per 100 admissions and 7.9 cases per 1000 patient-days during ICU stay. The rates of ESBL-E carriage or infection were 0.4 new case per 100 admissions and 3.9 cases per 1000 patient-days during ICU stay. Importation of MRSA increased significantly over time from 3.2 new cases per 100 admissions during the first 3 years to 5.5 during the last 3 years. The rate of ICU-acquired ESBLE decreased from 5.5 cases per 1000 patient-days during the first 3 years to 1.9 cases during the last 3 years. Nasal and digestive decontamination had low efficacy in eradicating carriage.

Conclusions: MRSA remained poorly controlled throughout the hospital and was not just a problem in the ICU. MRSA thus requires more effective measures throughout the hospital. ESBL-E was mainly an ICU pathogen and our approach resulted in a clear decrease in the rate of acquisition in the ICU over time.