Background: Nursing home (NH) residents are commonly colonized by Staphylococcus aureus, multidrug-resistant gram-negative bacilli and Clostridium difficile, but the incidence of infection caused by these organisms is not well-described. We quantified the burden of these infections in local NH and the time to infection post-hospital discharge, using surveillance data from the Centers for Disease Control and Preventions Emerging Infections Program.
Methods: In 2016, surveillance for invasive methicillin-resistant and sensitive S. aureus (MRSA/MSSA), carbapenem-resistant Enterobacteriaceae (CRE), and C. difficile infections (CDI) was performed in 34 NH (bed size range: 28-566) in Monroe County, New York. Incident cases were defined as positive specimens collected in the NH or ≤ 3 days after hospital admission from a NH. Surveillance was limited to sterile sites for MRSA/MSSA; CRE included sterile sites and urine. NH bed census data was used to calculate incidence.
Results: A total of 205 cases in 193 persons were identified in 29 NH. CDI was most common with 156 (76%) cases identified; followed by MRSA (24, 12%), MSSA (17, 8%) and CRE (8, 4%). Cases were mainly female (61%) and White (80%) with a mean Charlson score of 5 (SD=3). CDI cases were older with a median age of 81 years (p=0.0007). Twenty-seven (79%) of the NH had a least one case of CDI; 11 (32%) MRSA; 10 (29%) MSSA; and 7 (12%) CRE. Three (9%) NH had at least one case of all organisms.
Incidence (per 100,000 resident days) pooled across NH ranged from 2.4 to 33.3, with incidence differing from expected in 5 (15%) NH (Figure 1). Incidence by NH was highest for CDI: range 2.4-23.6 (median= 7.7), MRSA: 2.0-5.8 (median=3.1), MSSA: 1.5-8.3 (median=2.4) and CRE: 0.6-3.8 (median=2.0). Forty-eight percent of cases developed within 30 days of hospital discharge (median=13 days (25%-75% IQR=12)).
Conclusion: Incidence varied between organisms and NH; several NH had higher than expected rates of infection. Additionally, 48% of cases were detected shortly after hospital transfer to the NH. These findings highlight possible predictors of infection and prevention targets at both the nursing home and patient-level. Further analysis adjusting for NH characteristics including case mix index and number of transfers from the hospital is needed.
C. Concannon, None
A. Gellert, None
D. Nelson, None
G. Dumyati, None
C. B. Felsen, None