Multidrug-resistant Acinetobacter baumannii infections in COVID-19 patients hospitalized in intensive care unit

Infection. 2022 Feb;50(1):83-92. doi: 10.1007/s15010-021-01643-4. Epub 2021 Jun 27.


Objectives: Superinfections in patients hospitalized in intensive care unit (ICU) are an important and challenging complication, also in COVID-19. However, no definitive data are available about the role of multidrug-resistant Acinetobacter baumannii (MDR-AB) in COVID-19.

Methods: This was a single-center, cross-sectional study including patients with MDR-AB infections admitted to ICU with or without COVID-19, between January 2019 and January 2021. The primary objective of the study was to evaluate risk factor for MDR-AB infections in ICU patients hospitalized for COVID-19 or other etiology. The secondary endpoints were 30-days mortality in all study population and risk factors associated with development of bloodstream infection (BSI).

Results: During the study period 32 adults with COVID-19 were enrolled and compared with 115 patients admitted in the same ICU for other reasons. We observed a total of 114 deaths, with a survival rate of 29.3%: 18.8% in COVID-19 and 32.2% in control group. Relative risk for MDR-AB infection in COVID-19 showed that serum lactate levels mmol/l > 2, Acinetobacter baumannii colonization, BSI and steroid therapy were observed more frequently in COVID-19 patients. Cox regression analysis showed that serum lactate levels > 2 mmol/l, Acinetobacter baumannii colonization, BSI, and steroid therapy were associated with 30-days mortality. Finally, patients with COVID-19, white blood cells count > 11,000 mm3, serum lactate levels > 2 mmol/l, infections at time of ICU admission, Acinetobacter baumannii colonization, and steroid therapy were independently associated with development of BSI.

Conclusions: Our data highlight the impact of BSI on outcome, the role of Acinetobacter baumannii colonization and the use of steroids on the risk to develop MDR-AB infections also during COVID-19.

Keywords: Acinetobacter baumannii; Bacteraemia; COVID-19; Colonization; Steroids.

MeSH terms

  • Acinetobacter Infections* / drug therapy
  • Acinetobacter Infections* / epidemiology
  • Acinetobacter baumannii*
  • Anti-Bacterial Agents / pharmacology
  • Anti-Bacterial Agents / therapeutic use
  • COVID-19*
  • Cross Infection* / drug therapy
  • Cross Infection* / epidemiology
  • Cross-Sectional Studies
  • Drug Resistance, Multiple, Bacterial
  • Humans
  • Intensive Care Units
  • Risk Factors
  • SARS-CoV-2


  • Anti-Bacterial Agents