Low 30-day mortality and low carbapenem-resistance in a decade of Acinetobacter bacteraemia in South Sweden

Abstract

Background: The aim of this study was to provide a descriptive account of carbapenem resistance and risk factors for mortality from invasive Acinetobacter infections in the south of Sweden.

Methods: Blood isolates with growth of Acinetobacter species between 2010 and 2019 in Skåne county were subtyped using MALDI-TOF and subjected to susceptibility testing against clinically relevant antibiotics. Association between risk factors and 30-day mortality were analysed in univariate and multivariate logistic regression models.

Results: There were 179 bacteraemia episodes in 176 patients included in the study. The 30-day all-cause mortality was 16%. In all, two percent of Acinetobacter strains were carbapenem resistant. Independent risk factors associated with 30-day mortality in the multivariate regression model were Acinetobacter growth in all blood cultures drawn at the day of bacteraemia onset (OR 5.0, 95% CI: 1.8 to 13.7, p= 0.002), baseline functional capacity (1-4 points, OR 2.0, 95% CI: 1.2 to 3.4, p= 0.010) and correct empiric antibiotics at time of culture (OR 3.5 95% CI: 1.0 to 11.8, p= 0.045).

Conclusion: This study on Acinetobacter bacteraemia in South Sweden found low 30-day mortality and low carbapenem-resistance rates compared to previous international studies which may be due to a higher rate of contaminant findings.

Keywords: Antimicrobial resistance; MALDI-TOF; blood stream infections; nosocomial infection; opportunistic infections.