Central-line-associated bloodstream infections, multi-drug-resistant bacteraemias and infection control interventions: a 6-year time-series analysis in a tertiary care hospital in Greece

Central-line-associated bloodstream infections (CLABSIs) are serious healthcare-associated infections with substantial morbidity and hospital costs. To investigate the association between the incidence of CLABSIs, the implementation of specific infection control measures, and the incidence of multi-drug-resistant (MDR) bacteraemias in a tertiary care hospital in Greece from 2013 to 2018. Analysis was applied for the following indices, calculated monthly: CLABSI rate; use of hand hygiene disinfectants; isolation rate of patients with MDR bacteria; and incidence of bacteraemias [total Gram-negative carbapenem-resistant Acinetobacter baumanii, carbapenem-resistant Pseudomonas aeruginosa and carbapenem-resistant Klebsiella pneumoniae; and Gram-positive meticillin-resistant Staphylococcus aureus and vancomycin-resistant enterococci]. The total number of bacteraemias from carbapenem-resistant Gram-negative pathogens was significantly correlated with an increased CLABSI rate for all (total) hospital departments [incidence rate ratio (IRR) 1.17, 95% confidence interval (CI) 1.05–1.31, P=0.006] and the adult intensive care unit (ICU) (IRR 1.37, 95% CI 1.07–1.75, P=0.013). In the adult ICU, every increase in the incidence of each resistant Gram-negative pathogen was significantly correlated with a decreased CLABSI rate (carbapenem-resistant A. baumanii: IRR 0.59, 95% CI 0.39–0.90, P=0.015; carbapenem-resistant K. pneumoniae: IRR 0.48, 95% CI 0.25–0.94, P=0.031; carbapenem-resistant P. aeruginosa: IRR 0.54, 95% CI 0.33–0.89, P=0.015). The use of hand disinfectants was correlated with a decreased CLABSI rate 1–3 months before the application of this intervention for all (total) hospital departments (IRR 0.80, 95% CI 0.69–0.93, P=0.005), and for scrub disinfectants in the current month for the adult ICU (IRR 0.34, 95% CI 0.11–1.03, P=0.057). Isolation of patients with MDR pathogens was not associated with the incidence of CLABSIs. Hand hygiene was associated with a significant reduction in the incidence of CLABSIs at the study hospital. Time-series analysis is an important tool to evaluate infection control interventions.