SEPTIC EPISODES CAUSED BY ACINETOBACTER BAUMANNII, KLEBSIELLA PNEUMONIAE AND PSEUDOMONAS AERUGINOSA IN A TERTIARY HOSPITAL IN 2018-2020: TRENDS AND CONSIDERATIONS

Abstract

Intro: This study aimed at evaluating healthcare-related sepses caused by three multi-drug resistant Gram-negative bacteria (Acinetobacter baumannii, Klebsiella pneumoniae and Pseudomonas aeruginosa) in a tertiary hospital in 2018-2020, particularly concerning therapy, antibiotic-resistance and outcomes, by also comparing the pre-COVID (2018-2019) and COVID (2020) periods. Methods: An observational, retrospective-cohort analysis was based on data related to patients admitted to the “SS. Antonio e Biagio e Cesare Arrigo” Hospital in Alessandria (Italy) between 2018 and 2020, with septic episodes from bacteria of the examined species, whose antibiogram proved resistance to ≥ 2 antimicrobial classes indicated by the European Centre for Disease Prevention and Control. Data were retrieved from patients’ medical records and the hospital's computer-based application. Statistics involved Fisher-test comparisons and cumulative incidence analyses. Findings: Inclusion criteria led to enrolment of 174 patients. Comparison between 2020 and 2018-2019 showed a relative increase in A. baumannii cases, at the expense of the other species (p<0.0001), and an increasing resistance trend for K. pneumoniae, with a higher proportion of cases resistant to 3-4 classes of antimicrobials (p<0.0001). Overall, most patients were treated with carbapenems (72.4%), although the COVID period saw a significant rise in the use of polymyxins, particularly colistin (62.5% vs 36%, p=0.0005). In both periods, more than half patients recovered (53-57%) and around one third died (27-34%), but with different outcomes according to the infecting bacterium, generally better for P. aeruginosa (70% recovered at 60 days) and worse for A. baumannii (55% recovered). Discussion: The study confirmed the importance of the burden connected to healthcare-related sepses. Moreover, since the COVID outbreak, a trend could be spotted towards higher relative incidence of complex cases, caused by antimicrobial-resistant bacteria and thus requiring second-line therapy. Conclusion: These findings underline the importance of appropriate antimicrobial stewardship and infection control in view of the evolving healthcare needs.