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. 2021 Mar;42(3):305-310.
doi: 10.1017/ice.2020.450. Epub 2020 Sep 30.

Epidemiology and clinical outcomes associated with extensively drug-resistant (XDR) Acinetobacter in US Veterans' Affairs (VA) medical centers

Margaret A Fitzpatrick  1   2 , Katie J Suda  3   4 , Linda Poggensee  1 , Amanda Vivo  1 , Marissa Wirth  1 , Geneva Wilson  1 , Martin Evans  5 , Charlesnika T Evans  1   5   6   7
Affiliations

Epidemiology and clinical outcomes associated with extensively drug-resistant (XDR) Acinetobacter in US Veterans' Affairs (VA) medical centers

Margaret A Fitzpatrick et al. Infect Control Hosp Epidemiol. 2021 Mar.

Abstract

Objective: Although infections caused by Acinetobacter baumannii are often healthcare-acquired, difficult to treat, and associated with high mortality, epidemiologic data for this organism are limited. We describe the epidemiology, clinical characteristics, and outcomes for patients with extensively drug-resistant Acinetobacter baumannii (XDRAB).

Design: Retrospective cohort study.

Setting: Department of Veterans' Affairs Medical Centers (VAMCs).

Participants: Patients with XDRAB cultures (defined as nonsusceptible to at least 1 agent in all but 2 or fewer classes) at VAMCs between 2012 and 2018.

Methods: Microbiology and clinical data was extracted from national VA datasets. We used descriptive statistics to summarize patient characteristics and outcomes and bivariate analyses to compare outcomes by culture source.

Results: Among 11,546 patients with 15,364 A. baumannii cultures, 408 (3.5%) patients had 667 (4.3%) XDRAB cultures. Patients with XDRAB were older (mean age, 68 years; SD, 12.2) with median Charlson index 3 (interquartile range, 1-5). Respiratory specimens (n = 244, 36.6%) and urine samples (n = 187, 28%) were the most frequent sources; the greatest proportion of patients were from the South (n = 162, 39.7%). Most patients had had antibiotic exposures (n = 362, 88.7%) and hospital or long-term care admissions (n = 331, 81%) in the prior 90 days. Polymyxins, tigecycline, and minocycline demonstrated the highest susceptibility. Also, 30-day mortality (n = 96, 23.5%) and 1-year mortality (n = 199, 48.8%) were high, with significantly higher mortality in patients with blood cultures.

Conclusions: The proportion of Acinetobacter baumannii in the VA that was XDR was low, but treatment options are extremely limited and clinical outcomes were poor. Prevention of healthcare-associated XDRAB infection should remain a priority, and novel antibiotics for XDRAB treatment are urgently needed.

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Figures

Figure 1.
Figure 1.. Antibiotic susceptibility of XDR Acinetobacter isolates
Percent of XDRAB isolates testing susceptible to key antibiotics. Individual antibiotics are grouped into relevant classes by color.
Figure 2.
Figure 2.. Geographic distribution of XDR Acinetobacter
Geographic distribution of patients with XDRAB cultures in VAMCs. Circle size corresponds to the number of patients with XDRAB cultures at VAMCs in that state or territory (Puerto Rico). Varying color shades indicate U.S. Census Bureau regions.
See this image and copyright information in PMC

References

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