Active surveillance and use of barrier precautions did not reduce colonization and infection with MRSA and VRE in adult ICUs

Morris A. — Tue, 16 Aug 2011 00:00:00 GMT

Question

In adult intensive care units (ICUs), does culture-based active surveillance and expanded use of barrier precautions reduce colonization and infection with methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant enterococcus (VRE)?

Methods

Design

Cluster-randomized controlled trial (Strategies to Reduce Transmission of Antimicrobial Resistant Bacteria in Intensive Care Units [STAR*ICU]). ClinicalTrials.gov NCT00100386.

Allocation

{Concealed}*.†

Blinding

Unblinded.†

Follow-up period

Until ICU discharge.

Setting

19 adult medical, surgical, or medical-surgical ICUs with ≥ 1200 patient-days in a 6-month period and an estimated incidence of ≥ 9 events of MRSA or VRE colonization or infection per 1000 patient-days in the USA.

Patients

3488 patients with an ICU stay ≥ 3 days and a surveillance culture obtained ≤ 2 days after ICU admission. Exclusion criteria included history of colonization or infection during the past year and positive clinical or surveillance culture ≤ 2 days after ICU admission.

Intervention

Surveillance and barrier precautions (n = 10 ICUs, 2132 patients) or control (n = 9 ICUs, 1356 patients). Patients in intervention ICUs received surveillance nasal swabs for MRSA cultures and stool or perianal swabs for VRE cultures ≤ 2 days after ICU admission, weekly, and ≤ 2 days before or after ICU discharge. Results were available via a Web-based system. Patients infected or colonized with MRSA or VRE during the previous year or during the ICU stay were cared for in isolation with contact precautions until ICU discharge. Other patients were cared for with universal gloving until results of admission surveillance cultures were both negative, in which case standard precautions were used. Patients in control ICUs were swabbed for surveillance cultures, but results were not available to ICU staff. Standard precautions were used except for patients who were identified, by existing hospital procedures, as infected or colonized with MRSA or VRE. Isolation procedures were used with these patients.

Outcomes

Incident colonization or infection with either MRSA or VRE. Secondary outcomes included incident colonization or infection with MRSA and with VRE separately.

Patient follow-up

100% of patients; 95% of ICUs.

Main results

The intervention and control groups did not differ for any of the main outcomes (Table). Patients who were colonized or infected with MRSA or VRE were assigned to barrier precautions more frequently in intervention ICUs (92%) than in control ICUs (38%).

Conclusion

In adult intensive care units, culture-based active surveillance and expanded use of barrier precautions did not reduce incidence of colonization and infection with methicillin-resistant Staphylococcus aureus and vancomycin-resistant enterococcus.Active surveillance and barrier precautions (intervention) vs control in adult intensive care units (ICUs)‡OutcomesMean number of events per 1000 patient-d at risk§P valueIntervention ICUsControl ICUsIncident MRSA or VRE infection or colonization40.435.60.35Incident MRSA infection or colonization16.013.50.39Incident VRE infection or colonization38.933.40.53‡MRSA = methicillin-resistant Staphylococcus aureus (MRSA); VRE = vancomycin-resistant enterococcus.§Adjusted for baseline incidence.

Annals of Internal Medicine: MRSA Topic Collection

Active surveillance and use of barrier precautions did not reduce colonization and infection with MRSA and VRE in adult ICUs