Acinetobacter baumannii Isolates from COVID-19 Patients in a Hospital Intensive Care Unit: Molecular Typing and Risk Factors

Abstract

Infections caused by <i>Acinetobacter baumannii</i> represent a major concern for intensive care unit (ICU) patients. However, the epidemiology of these infections among COVID-19 patients has not been fully explored. The aims of this study were (i) to characterize the clonal spread of <i>A. baumannii</i> among COVID-19 patients admitted to the ICU of the Umberto I hospital of Rome during the first year of the pandemic and (ii) to identify risk factors for its acquisition. Isolates were analysed by pulsed-field gel electrophoresis, and a multivariable regression model was constructed. Adjusted odds ratios (aORs) and 95% confidence intervals (CIs) were calculated. Overall, 193 patients were included, and 102 strains were analysed. All isolates had highly antibiotic-resistant profiles and derived from two genotypes. The cumulative incidence of <i>A. baumannii</i> acquisition (colonization or infection) was 36.8%. Patients with <i>A. baumannii</i> had higher mortality and length of stay. Multivariable analysis showed that previous carbapenem use was the only risk factor associated with <i>A. baumannii</i> acquisition (aOR: 4.15, 95% CI: 1.78-9.64). We documented substantial <i>A. baumannii</i> infections and colonization and high levels of clonal transmission. Given the limited treatment options, effective prevention and containment strategies to limit the spread of <i>A. baumannii</i> should be implemented.