A retrospective analysis of Klebsiella bloodstream infections in critically ill patients over a five-year period

ABSTRACT

Introduction: This study aimed to identify Klebsiella spp. bloodstream infections (KBSIs) in critically ill patients, characterising potential risk factors and targets for intervention. Methods: A retrospective analysis of blood cultures submitted to the Clinical Microbiology and Public Health Laboratory between 2015 and 2020, together with data from the Public Health England Data Capture System, was performed to identify KBSIs. Electronic patient records were reviewed for potential sources and risk factors. Results: Klebsiella spp. were the second leading cause of Gram-negative BSIs in critically ill patients, after E. coli (82 KBSIs over five years). Almost two-thirds (62.2%) were nosocomial. Median age was 64.3 years (IQR 50.2–71.2), 62.2% were male and case fatality rate was 22%. Comorbidities included ‘Cardiovascular’ (48.8%), ‘Respiratory’ (37.8%), ‘Gastrointestinal’ (37.8%), ‘Endocrine’ (35.4%) and ‘Surgery’ (35.4%). Common sources were ‘Line’ (36.6%), ‘Urinary Tract’ (25.6%) and ‘Gastrointestinal’ (11.0%). 54.3% of sputum/BAL, 33.3% of line and 14.9% of urine cultures grew Klebsiella within 2 weeks of a KBSI. Ventilator use (76.5%) and pneumonia (51.0%) were common prior to hospital-onset KBSIs. KBSIs numbers peaked in April-June 2020, coinciding with the first wave of COVID-19. Discussion: This study presents a current overview of characteristics of KBSIs in critically ill patients. We speculate that the high rates of positive sputum/BAL and line cultures associated with nosocomial infections, signify pneumonia and subsequent line contamination as a potential cause of KBSIs. This could have important consequences in context of the COVID-19 pandemic and highlights the importance of intravascular catheter care in the prevention of KBSIs.