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

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 mm(3), 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.