# P-1063. Morbidity and Mortality Analysis of Carbapenem-Resistant versus Carbapenem-Susceptible Acinetobacter baumannii infections in patients hospitalized at an Academic Hospital from 2019-2023

## TL;DR

The study compares outcomes of carbapenem-resistant and carbapenem-susceptible Acinetobacter baumannii infections in hospitalized patients, finding higher resource use but no significant difference in mortality.

## Contribution

The study provides U.S.-specific data on morbidity and mortality of CRAB infections, highlighting increased resource use and trends in mortality.

## Key findings

- CRAB infections were associated with longer hospital stays and higher resource use.
- No significant difference in 30- or 90-day mortality was found between CRAB and CSAB.
- Trends suggest higher 90-day infectious mortality in CRAB subgroups.

## Abstract

Carbapenem-resistant Acinetobacter baumannii (CRAB) is an international health concern, leading to prolonged hospital stays and increased mortality. Global data highlight increased financial and clinical impacts of CRAB, reinforcing the need for surveillance and antimicrobial stewardship to combat this growing threat. Data of CRAB infections is sparse within the U.S. regarding mortality, length of stay (LOS), and cost factors.Table 1Baseline characteristicsTable 2Cost Factors

Baseline characteristics

Cost Factors

All inpatient cases of A. baumannii at our institution from 2019-2023 were retrospectively reviewed. Patients aged ≥ 18 with isolation of A. baumannii from a non-urinary source with meropenem MIC ≥ 8 or ≤ 2 were included. Primary outcome was 90-day mortality. Secondary outcomes included 30-day mortality, LOS, and additional cost factors. Analysis used JASP Statistical Software. Logistic regression was used to adjust for age, CCI, and infection type.Table 3Outcome/Mortality DataTable 490 and 30-day Infectious Mortality

Outcome/Mortality Data

90 and 30-day Infectious Mortality

181 A. baumannii isolates were included for analysis. CRAB patients had a higher CCI, rates of paraplegia, recent hospitalizations, recent SNF/LTACH stays, and recent IV antibiotic use, detailed in Table 1. The CRAB cohort had a longer LOS, ICU LOS, longer antibiotic courses (25.12 vs. 13.95 days, p < 0.01), and infectious-related readmissions, detailed in Table 2. CRAB patients had more cultures, imaging, surgeries, and specialty consultations.

Our study indicated no overall significant differences in infectious-related mortality at 90 days (aOR=1.78 ,p=0.240) or 30 days (aOR=1.10, p=0.867) when adjusted for age, CCI, and infection type. However, CRAB had a statistically greater 90-day infectious-related mortality rate if surviving at 30 days (OR=8.27, p=0.022). Additionally, wound infections had significantly greater 90-day infectious mortality for CRAB vs. Carbapenem-susceptible A. baumannii (CSAB) (OR=6.04, p=0.03). There were no significant differences in mortality for CRAB vs. CSAB for other infection types.

CRAB infections were linked to greater morbidity and significantly higher resource use. There was no statistically significant difference in 30- and 90-day mortality, though trends indicate higher 90-day infectious mortality in multiple CRAB subgroup analysis. These findings highlight the need for continued A. baumannii investigation.

All Authors: No reported disclosures