We performed a longitudinal analysis of 661 methicillin-resistant Staphylococcus aureus (MRSA) isolates obtained from patients in a long-term care facility. USA300 clone increased from 11.3% of all MRSA isolates in 2002 to 64.0% in 2006 (p<0.0001) and was mostly recovered from skin or skin structures (64.3% vs. 27.0% for non-USA300 MRSA; p<0.0001).

We performed a longitudinal analysis of 502 unique methicillin-resistant Staphylococcus aureus (MRSA) clinical isolates originating from San Francisco jail inmates between 2000 and 2007. Strain USA300, first encountered in 2001, accounted for 82.1% (412/502) of MRSA infections. Non-USA300 MRSA strains were rarely found after 2005 (one isolate in 2006, three in 2007).

Assignment of patients to multiple-bed rooms on general medical and surgical wards was not associated with an increased risk in the development of HO-CDI. Future investigation should be performed with larger cohorts in multiple sites to more definitively address the question because this issue could have implications for patient room assignment and hospital design.

BackgroundFew studies have directly examined the link between assignment to a multi-bed vs. single-bed room and the risk for hospital onset C. difficileinfection (HO-CDI). Therefore, in this case–control study, we investigated whether assignment to a single-bed room reduced the risk of HO-CDI in adult inpatients on medical/surgical floors.MethodsConsecutive cases of HO-CDI, defined as adult patients admitted to San Francisco General Hospital with a new positive C. difficile stool test >72 hours after admission, were identified for the period between January 1, 2010 to December 31, 2015. Patients who first tested positive for C. difficilein the ICU or who had a history of CDI within the last 12 months were excluded. Controls were selected from the general medical/surgical inpatient population using incidence density sampling and matched to cases on the basis of admission unit and length of admission. A multi-bed room was defined as any room with one or more roommates. A multivariate cox proportional hazard model was used to estimate the relationship between room assignment (single vs. multi-bed) and development of HO-CDI. Variables included in the model, on the basis of a directed acyclic graph, were length of admission, HIV infection, and age.Results184 cases and 373 controls were identified during the study period. The median ages of cases and controls were 60 years and 56 years, and mean Charlson comorbidity scores were 3.8 and 3.7, respectively. The hazard ratio for the development HO-CDI associated with multi-bed room exposure was 2.32 (P = 0.03) with a 95% CI for the hazard ratio of 1.05 to 5.17.ConclusionIn this study, assignment of patients to multi-bed rooms on general medical and surgical wards was associated with an increased hazard for the development of HO-CDI. This finding, especially if confirmed in other institutions, could have implications for patient room assignment and hospital design.Disclosures All authors: No reported disclosures.