Risk Factors, Clinical Presentation, and Outcome of Acinetobacter baumannii Bacteremia

Abstract

Infections caused by Acinetobacter baumannii (AB), an increasingly prevalent nosocomial pathogen, have been associated with high morbidity and mortality. We conducted this study to analyze the clinical features, outcomes, and factors influencing the survival of patients with AB bacteremia. We retrospectively examined the medical records of all patients developing AB bacteremia during their hospital stay at a tertiary care hospital in Beirut between 2010 and 2015. Ninety episodes of AB bacteremia were documented in eighty-five patients. Univariate analysis showed that prior exposure to high dose steroids, diabetes mellitus, mechanical ventilation, prior use of colistin and tigecycline, presence of septic shock, and critical care unit stay were associated with a poor outcome. High dose steroids and presence of septic shock were significant on multivariate analysis. Crude mortality rate was 63.5%. 70.3% of the deaths were attributed to the bacteremia. On acquisition, 39 patients had septicemia. Despite high index of suspicion and initiation of colistin and/or tigecycline in 18/39 patients, a grim outcome could not be averted and 37 patients died within 2.16 days. Seven patients had transient benign bacteremia; three of which were treated with removal of the line. The remaining four did not receive any antibiotics due to withdrawal of care and died within 26.25 days of acquiring the bacteremia, with no signs of persistent infection on follow up. A prolonged hospital stay is frequently associated with loss of functionality, and steroid and antibiotic exposure. These factors seem to impact the mortality of AB bacteremia, a disease with high mortality rate and limited therapeutic options.

Comparison of Septic Shock Due to Multidrug-Resistant Acinetobacter baumannii or Klebsiella pneumoniae Carbapenemase-Producing K. pneumoniae in Intensive Care Unit Patients

“…We found an association between exposure to steroid therapy and development of MDR-AB infection. This distinguishing feature of MDR-AB infections was recently reported by Ballouz and coworkers (39), but the meaning of this association is not yet understood. Since most of patients with MDR-AB infection had pneumonia (69.6%), it is possible that the link between steroid use and MDR-AB infection might be due to steroid administration in the management of severe pneumonia to reduce inflammation (40).…”

Spatio-Temporal Distribution of Acinetobacter baumannii in Germany—A Comprehensive Systematic Review of Studies on Resistance Development in Humans (2000–2018)

“…An identical macrorestriction pattern (PFGE-type) was detected in isolates of two different hospitals in 2008 in North Rhine-Westphalia confirming that inter-hospital transmission is possible [26]. Moreover, a prolonged hospital stay is frequently associated with exposure to antibiotics [68]. A. baumannii can rapidly acquire resistance by mutation during antimicrobial therapy [44].…”

Acinetobacter spp in a Third World Country with Socio-economic and Immigrants Challenges

“…One study, addressing patients with neutropenic fever have found that increased in-hospital mortality rate was associated with the duration of neutropenia and treatment modification for clinical deterioration [26]. Moreover, in concordance with previous worldwide studies, Ballouz et al found that prolonged hospital stay that is often associated with a loss of functionality, as well as antibiotic and steroid exposure especially in critically ill patients, increases the risk of exhibiting A. baumannii bacteremia with poor outcome [27]. Dahdouh et al conducted a study on ninetyfive A. baumannii strains isolated from a tertiary care center in Beirut and showed that their virulence profiles were highly variable and without a specific pattern [28].…”

“…Few years later, carbapenem resistant Acinetobacter species started to emerge in this same hospital [32] [34]. A study conducted at a major tertiary care center in Beirut showed that the majority (82/90) of A. baumannii isolated from patients with bacteremia were resistant to carbapenem but remained susceptible to tigecycline and colistin [27]. In this study, colistin susceptibility was tested by the Kirby-Bauer technique [27]; this technique is not considered accurate for testing the susceptibility to colistin.…”

“…A study conducted at a major tertiary care center in Beirut showed that the majority (82/90) of A. baumannii isolated from patients with bacteremia were resistant to carbapenem but remained susceptible to tigecycline and colistin [27]. In this study, colistin susceptibility was tested by the Kirby-Bauer technique [27]; this technique is not considered accurate for testing the susceptibility to colistin. On the contrary, MIC determination should be implemented in order to correctly assess the level of colistin resistance [35].…”