Social and clinical predictors of perianal colonisation by multidrug-resistant bacteria for geriatric patients in the internal medicine service.

Background: Colonisation by multidrug-resistant (MDR) bacteria is a global health issue. The identification of patients with a higher risk of colonisation is essential. Patients admitted to internal medicine services might represent a vulnerable population with a high risk of colonisation. This study was the first to assess social and clinical variables associated with a higher risk of perianal colonisation by MDR bacteria in a Spanish cohort of patients admitted to internal medicine service.

Methods: Patients admitted to an internal medicine service during 12 months of recruitment (1 March 2022 to 1 March 2023) were included in the study. Perianal swabs were performed at admission to identify the presence of MDR bacteria. Social and clinical variables were collected following a directed acyclic graph. A cluster analysis was performed to identify clinical profiles of higher risk. Bivariate analyses and multivariable logistic regression models were fitted to identify potential predictors of MDR bacteria colonisation.

Results: A total of 245 patients, according to the required sample size, were included. Of them, 46 (18.8%) were colonised by MDR bacteria in perianal swabs. Female sex, age > 80 years, dependency on activities of daily living, cognitive deterioration and living in long-term care facilities constituted the highest risk clinical profile. After adjustments, living in long-term care facilities and malnutrition remained the main risk factors identified.

Conclusion: Patients admitted to internal medicine services presented a high frequency of perianal colonisation by MDR bacteria. Social and clinical variables associated with bio-psycho-social susceptibility were associated with colonisation. Special surveillance is needed in internal medicine services to control the transmission.