Can Decolonization Prevent Post-Discharge MRSA Infections?

Published - Written by Angela Chen, MBBS, MPH

Ryan is a 28-year-old man who was recently admitted by the orthopedic team with fractures to his right tibia and fibula from a motorcycle accident. Ryan also required skin grafting for his injuries. Just prior to discharge, he was screened for methicillin-resistant Staphylococcus aureus (MRSA) colonization as part of routine hospital surveillance and infection control. His MRSA culture came back positive. 

MRSA is a most common cause of skin, soft-tissue, and procedure-related infection. Previous studies have shown that MRSA decolonization reduces the rates of surgical-site infection and recurrent skin infections. In patients like Ryan, the best approach to MRSA decolonization is uncertain. Should the approach be based on decolonization or education about personal and environmental hygiene?

A recently published trial in NEJM by Huang et al. addressed this question in a multicenter, randomized, controlled trial. The authors compared post-discharge hygiene education plus decolonization with hygiene education alone. The results showed that post-discharge decolonization with chlorhexidine and mupirocin reduced the risk of MRSA infection, compared with education alone.

The following NEJM Journal Watch summary explains the study and its findings.


Postdischarge MRSA Decolonization to Prevent Infections

Richard T. Ellison III, MD reviewing Huang SS et al. N Engl J Med 2019 Feb 14

Patients who are carriers of methicillin-resistant Staphylococcus aureus (MRSA) are at increased risk for subsequent MRSA infection after hospitalization. Investigators undertook a 3-year controlled trial to assess whether a post–hospital discharge decolonization regimen could decrease infection rates. Patients who had a positive culture for MRSA during or within 30 days before or after hospitalization at 17 California hospitals were randomized to have either hygiene education alone or education plus decolonization 5 days twice monthly, including daily bathing with 4% chlorhexidine, twice daily use of 0.12% chlorhexidine mouthwash, and twice daily application of 2% nasal mupirocin.

During 12 months of follow-up, 67 (6.3%) of 1058 decolonization patients and 98 (9.2%) of 1063 education patients developed MRSA infection (hazard ratio, 0.70, 95% confidence interval, 0.52–0.96); 85% of these infections led to hospitalization. Clinically judged infections from any cause were also lower in the decolonization group (19.6% vs. 23.7%), as was risk for infection-related hospitalization. Infection rates were lower in fully adherent versus partially adherent decolonization patients. Of 1591 postrecruitment MRSA isolates tested, 12.6% were mupirocin resistant, but study-emergent high-level resistance was comparable in the decolonization (1.4%) and education groups (1.6%).

COMMENT: This study shows a clear decrease in posthospitalization infections in MRSA carriers with relatively intensive decolonization. The total decolonization protocol duration raises concerns about cost and compliance. The findings mirror older data in hemodialysis patients carrying S. aureus (N Engl J Med 1986; 315:91). The findings prompt numerous other questions. As not all MRSA strains are comparable, was the decolonization effect more pronounced for carriers of the more pathogenic Panton–Valentine leukocidin (PVL)–positive community associated MRSA strains than for carriers of PVL-negative MRSA? Might decolonization also be appropriate for carriers of PVL-positive methicillin-susceptible S. aureus isolates? Given that the rate of all infections and not simply MRSA infections decreased, could a program of chlorhexidine bathing alone be effective, at a lower cost and without the risk of inducing mupirocin resistance?


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 Angela is a 2018-2019 NEJM editorial fellow. She is an endocrine fellow who trained at Flinders Medical Centre and the Royal Adelaide Hospital. Angela recieved her medical degree from the University of Adelaide, and masters of public health from the University of Sydney. Her clinical and research interests are in the areas of glucocorticoid and cardiovascular endocrinology and diabetes medicine.