Epidemiology, Clinical Characteristics and Treatment Outcomes of Acinetobacter baumannii Infection at a Regional Hospital in Thailand

Objective: This retrospective cohort study evaluated the treatment outcome of Acinetobacter baumannii infection. Methods: In this retrospective cohort study, 476 patients with Acinetobacter baumannii (A. baumannii) infection who were admitted to the internal medicine ward at Lampang Hospital, Lampang, Thailand, from 1 January 2020 to 31 December 2020 were enrolled. Medical records were reviewed. Results: A total of 476 patients with A. baumannii infection were enrolled. Of these, 204 (43%) survived, while 272 (57%) died. Extensively drug-resistant (XDR) A. baumannii with hospital-acquired pneumonia was the most common presentation. Risk factors for acquiring multidrug-resistant (MDR) pathogens included previous hospitalization or antibiotic use and the presence of an indwelling urinary catheter, which was common in both survived and deceased groups. The survival group was significantly more likely to have received appropriate antibiotic therapy compared to the deceased group (71% vs 51%; p <0.001), particularly with colistin mono- therapy (34% vs 18%; p <0.001). Additionally, multivariate analysis showed that predictors of unfavorable outcomes, such as multiorgan failure, hypoalbuminemia, hematologic malignancy, and healthcare-associated pneumonia. The survival group had a significantly longer hospital stay compared to the deceased group (15 days vs 7 days; p <0.001) and also showed an increased microbiological cure rate (49% vs 26%; p <0.001). Conclusion: XDR A. baumannii leads to serious nosocomial infections. Understanding the risk factors for XDR A. baumannii infections could enhance colistin prescription prior to the antimicrobial susceptibility testing results.