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The following is a summary of “Clinical burden of Acinetobacter baumannii, including carbapenem-resistant A. baumannii, in hospitalized adult patients in the USA between 2018 and 2022,” published in the April 2025 issue of BMC Infectious Diseases by Lodise et al. 

Researchers conducted a retrospective study to describe the incidence of Acinetobacter baumannii and carbapenem-resistant A. baumannii (CRAB) across United States (US) hospitals from January 1, 2018, to December 31, 2022.  

They used microbiology data from the PINC AI^TM Database to assess the incidence rates of A. baumannii and CRAB from January 1, 2018, to December 31, 2022, across US hospitals in each census region. Rates were determined at both the hospitalization encounter and individual levels, and CRAB was defined as non-susceptibility to doripenem, imipenem, or meropenem. Demographics, comorbidities, and in-hospital mortality were compared between patients with CRAB and carbapenem-susceptible A. baumannii (CSAB) at the hospitalization encounter level.  

The results showed that 7,270 hospitalization encounters with ≥ 1 A. baumannii clinical cultures were identified. The overall incidence of A. baumannii was 1.19 cases per 100 hospitalization encounters and 1.33 cases per 100 unique patients. For CRAB, 2,708 hospitalization encounters were recorded, with an incidence rate of 0.44 cases per 100 encounters. The West South Central, East North Central, and East South-Central regions had the highest CRAB incidence rates (0.78, 0.67, and 0.63 cases per 100 hospitalization encounters, respectively). Compared with CSAB, patients with CRAB had more positive cultures (20.9% vs 10.0%, P < 0.0001) and a higher prevalence of other Gram-negative pathogens within ± 3 days of the index A. baumannii culture (47.2% vs 42.9%, P = 0.0004). In-hospital mortality was higher in patients with CRAB compared to patients with CSAB (20.5% vs 11.3%, P < 0.0001). 

Investigators concluded that A. baumannii was identified in a small percentage of adult hospitalizations across multiple US centers, with a significant proportion being carbapenem resistant (CR) and a higher incidence observed in central US regions. 

Source: bmcinfectdis.biomedcentral.com/articles/10.1186/s12879-025-10749-1