Universal Contact Precautions More Effective for Preventing MRSA Infection in the ICU

Researchers, in a poster presented at the 48th annual meeting of the Infectious Diseases Society of America (IDSA), suggest that universal contact precautions -- including the requirement that anyone caring for or visiting a MRSA patient must wear gloves and a gown -- were more effective at preventing infection among patients in intensive care units (ICUs) than were other strategies.

Gidengil, et al. (2010) acknowledge that evidence for the efficacy of strategies to prevent methicillin-resistant Staphylococcus aureus (MRSA) is mixed and that there is an urgent policy-related need for better evidence on the effectiveness and cost-effectiveness of strategies to prevent MRSA transmission in hospitals.

The researchers sought to estimate the health benefits and cost-effectiveness of interventions to prevent MRSA transmission among patients admitted to an ICU, and used a Markov microsimulation model for a hypothetical cohort of 100,000 adult patients admitted to an ICU. MRSA-prevention strategies that were tested in the study included standard precautions; universal contact precautions (CP); universal chlorhexidine gluconate (CHG) baths; universal decolonization (CHG baths and mupirocin); Universal CP plus universal CHG baths; and universal CP plus universal decolonization.

Gidengil, et al. (2010) assumed that:

-- 10 percent of patients were colonized on admission

-- Average ICU length of stay was four days

-- 0.5 percent to 1.5 percent acquire MRSA colonization/ICU day (depending on colonization prevalence)

-- 0.4 percent develop MRSA infection per colonization day

-- Efficacy of CP dependent on compliance

-- Efficacy of CHG 32 percent (transmission), 25 percent (infection)

-- Efficacy of decolonization 80 percent (transmission), 60 percent (infection)

-- Cost of CHG baths $2, cost of decolonization $5

-- Daily excess cost of MRSA infection $1,250

Based on the researchers' key assumptions, approximately 6,300 new cases of colonization and 470 MRSA healthcare-acquired infections HAIs occurred under standard precautions; in addition, universal CP with decolonization prevented the highest number of cases of MRSA colonization and infection. The researchers report that both universal CHG baths and universal decolonization were cost-saving compared to standard precautions from the hospital perspective, and that approximately 375,000 days of CP, 229,000 days of CHG baths, and 227,000 days of decolonization would be incurred when implementing these strategies.

The researchers conclude that under the current base case assumptions of initial MRSA prevalence of 10 percent and the efficacy and compliance associated with alternative strategies for prevention, universal CP with decolonization prevented

the highest number of cases of colonization and infection. They add that strategies that employ the use of CHG baths alone, or decolonization alone appear to be cost-saving compared to standard precautions alone. They say that additional work is needed to vary their key assumptions that might affect these preliminary results.

The authors of this poster are Courtney A. Gidengil, MD, MPH, of the Division of Infectious Diseases at Childrens Hospital Boston and RAND Corporation; Charlene Gay, BA, of the Department of Population Medicine, Harvard Pilgrim Health Care Institute and Harvard Medical School; Susan S. Huang MD MPH, of the University of California Irvine Medical School; Deborah Yokoe, MD, MPH, of the Channing Laboratory and of the Brigham and Womens Hospital; and Grace Lee, MD, MPH, of the Department of Population Medicine, Harvard Pilgrim Health Care Institute and Harvard Medical School, for the CDC Epicenters Program.

Reference: Gidengil CA, Gay C, Huang SS, Yokoe D and Lee G. Optimal Strategies to Prevent Methicillin-Resistant Staphylococcus aureus Transmission in Hospitals. Poster presented at the 48th annual meeting of the Infectious Diseases Society of America (IDSA).