An outbreak of multi-drug-resistant Acinetobacter baumannii on a burns ICU and its control with multi-faceted containment measures

Background: Patients in burns centres are at high risk of acquiring multi-drug-resistant organisms (MDROs) due to the reduced skin barrier and long hospital stay. Methods: This study reports the investigation and control of an outbreak of MDR Acinetobacter baumannii in a burns centre. The 27 patients hospitalized in the centre during the outbreak were screened regularly, and a total of 132 environmental samples were analysed to identify a potential source. Fourier-transform infra-red (FT-IR) spectroscopy and multi-locus sequence typing were applied to characterize the outbreak strain. Results: Between August and November 2022, the outbreak affected eight patients, with 11 infections and three potentially related fatal outcomes. An interdisciplinary and multi-professional outbreak team implemented a bundle strategy with repetitive admission stops, isolation precaution measures, patient screenings, enhanced cleaning and disinfection, and staff education. FT-IR spectroscopy suggested that the outbreak started from a patient who had been repatriated 1 month previously from a country with high prevalence of MDR A. baumannii. Environmental sampling did not identify a common source. Acquisition of the outbreak strain was associated with a higher percentage of body surface area with burn lesions ≥2a [per percent increase: odds ratio (OR) 1.05, 95% confidence interval (CI) 0.99–1.12; P=0.09], and inversely associated with a higher nurse-to-patient ratio (per 0.1 increase: OR 0.34, 95% CI 0.10–1.12; P=0.06). Conclusions: Burn patients with a higher percentage of body surface area with burn lesions ≥2a are at high risk of colonization and infection due to MDROs, particularly during periods of high workload. A multi-faceted containment strategy can successfully control outbreaks due to MDR A. baumannii in a burns centre.