Increased prevalence of and associated mortality with methicillin-resistant Staphylococcus aureus among hospitalized IBD patients.

Objectives: Methicillin-resistant Staphylococcus aureus (MRSA) infection has become increasingly prevalent in US hospitals, and the impact of MRSA on hospitalized inflammatory bowel disease (IBD) patients is unknown.

Methods: We used the Nationwide Inpatient Sample to identify admissions for IBD (n=116,842) between 1998 and 2004. We compared prevalence and in-hospital mortality of MRSA among IBD, non-IBD gastrointestinal (GI), and general medical inpatients.

Results: MRSA prevalence increased from 4.5/10,000 to 19.0/10,000 over the 7-year period (P<0.0001). After adjustment for confounders, IBD inpatients were at increased risk of MRSA compared with the non-IBD GI (adjusted odds ratio (aOR) 1.61; 95% confidence interval (CI): 1.33-1.96) and general medical (aOR 1.36; 95% CI: 1.11-1.66) groups. Of those with MRSA, catheter-related infections were specifically more common among IBD compared with non-IBD GI and general inpatients (28.8% vs. 11.0% and 8.5%, respectively, P<0.0002). Bowel surgery, parenteral nutrition, and health insurance were predictors of MRSA infection, but the first two became insignificant after controlling for length of stay (LOS). Compared with LOS < or = 7 days, MRSA was more likely among those hospitalized 8-21 days (aOR 7.40; 95% CI: 4.68-11.7) and >21 days (aOR 58.6; 95% CI: 36.0-95.3). MRSA infection was associated with sevenfold increase in mortality (aOR 7.61; 95% CI: 3.33-17.4).

Conclusions: Hospitalized IBD patients are at increased risk of MRSA compared with non-IBD GI and general medical inpatients. Increased mortality in the IBD population associated with MRSA reinforces the importance of measures to prevent nosocomial infection and to reduce length of hospitalization.