A carbapenem-resistant Acinetobacter baumannii (CRAB) outbreak in an intensive care unit (ICU) was contained by an improved infection-control measure that included a disinfectant policy. In our retrospective cohort study, we describe the epidemiological investigations and infection-control measures during this outbreak. Descriptive analysis was used to summarize patient demographics, neurological diseases, surgical treatment, underlying diseases, infection, and outcomes. In December 2023, two CARB-positive patients were observed in the ICU, and four more patients became CRAB-positive in January. During this outbreak, there was an overlap of hospitalization periods among the CRAB-positive patients, and CRAB was isolated from the environment; the isolated CRAB strain was identical. Infection-control measures, including hand hygiene, contact precautions and isolation, surveillance, decolonization, environmental cleaning, and disinfection, were reviewed and modified. The aim of this study was to examine the molecular background of the effectiveness of the disinfectant shift used during successful outbreak control. Experiments were carried out to study the phenotypic sensitivity and genetic background of different disinfectant agents. A thorough analysis of the detected CRAB strain included whole-genome sequencing (WGS), investigation of the qacE and qacEΔ1 genes’ relative expression by qPCR after exposure to different disinfectant solutions, as well as an analysis of biofilm formation. WGS analysis of the CRAB strain identified that an ST2 high-risk clone was responsible for the outbreak, which produced OXA-83 and ADC-30 beta-lactamases; in addition, qacE and qacEΔ1 genes were also detected, which confer resistance to disinfectants containing quaternary ammonium compounds (QACs). A qPCR analysis demonstrated that after exposure to different disinfectants, the gene expression levels of qacE and qacEΔ1 increased and correlated with concentrations of QACs of disinfectants. During the outbreak, the standard-of-care QAC-based disinfectant was changed to a mainly alcohol-based agent in the ICU, which contributed to the successful control of this outbreak, and no additional patients were identified with CRAB. We conclude that continuous surveillance and hand hygiene training combined with fast identification and reaction to new cases, as well as an in-depth analysis of multidrug-resistant outbreak strains and investigation of their disinfectant tolerance/resistance during an outbreak, are essential to effectively control the spread of nosocomial pathogens. The smart policy of disinfectant agent selection played a crucial role in controlling the outbreak and ensuring patient safety in the ICU.

Background: An external ventricular drain (EVD) is used to release elevated intracranial pressure by draining cerebrospinal fluid (CSF) from the brain’s ventricles. The establishment of an EVD is one of the most commonly performed neurosurgical procedures to treat intracranial pressure in patients. Nevertheless, infections are very frequent complications. Identifying the risk factors for EVD-related infections is a key to improving patient safety and outcomes. Methods: We conducted a retrospective, single-center study of patients who underwent EVD implantation between January 2022 and March 2024. Patients were classified into infected and non-infected groups based on their clinical symptoms, as well as laboratory and microbiological results. Patient characteristics and possible risk factors for infection were compared between the two groups. Results: In total, 123 patients treated with 156 EVDs were included in this study, with a mean age of 55.8 (range: 25–84) years. EVD-associated infections were observed in 37 patients (30%). We found no significant association between infection risk and patient characteristics, including gender, primary diagnosis, craniotomy, or immunosuppression. There was no significant difference in terms of EVD insertion, i.e., whether the insertion took place in the operating room (OR) with antibiotic prophylaxis or outside the OR with no periprocedural antibiotic treatment. However, within the intensive care unit (ICU), EVD infection was much lower (13%) if EVD insertion took place in a single-bed room compared to multiple-bed room insertions (34%). Furthermore, there were significant differences in terms of the duration of first EVD (both single and multiple catheterizations) (p < 0.0001) and the total catheterization time (p = 0.0001). Additionally, there was a significant association with patient days in the ICU and EVD catheterization. Conclusions: Revisiting infection control measures is necessary, with special attention to the replacement of EVDs in single-bed ICU rooms, to introduce antibiotic prophylaxis in the ICU. Minimizing unnecessary EVD manipulation during catheterization is crucial in order to decrease the risk of EVD infection.