Brain Abscess

Brain abscess is a severe intracranial infection associated with significant morbidity and mortality. Standard management combines neurosurgical intervention, when feasible, with prolonged intravenous antibiotic therapy. Neurosurgical procedures, such as surgical drainage or stereotactic aspiration, play a key role in reducing intracranial pressure, decreasing the infectious burden, and obtaining samples for microbiological identification. However, neurosurgical intervention is not always possible due to technical limitations or patien related contrindications. In these situations, microbiological documentation becomes particularly challenging. Conventional diagnostic methods have limited sensitivity, with blood cultures and lumbar puncture yielding positive results in only about 25% of brain abscess cases. Recent advances in infectious disease diagnostics have introduced metagenomic approaches that may improve pathogen detection. Studies have shown that metagenomic analysis of operative samples can provide more comprehensive microbiological documentation than conventional culture-based methods. In addition, next-generation sequencing (NGS) of circulating microbial cell-free DNA in blood enables the detection of short microbial DNA fragments with a short half-life, reflecting active infection. This technology has already demonstrated promising results in clinical situations where microbiological documentation is difficult, such as febrile neutropenia. The present study aims to evaluate the performance of this approach in patients with brain abscess.

Brain abscess is a focal bacterial or fungal infection of the brain. Treatment is neurosurgical drainage of pus followed by long-term antibiotic treatment. In spite of successful treatment of the infection, long-term cognitive problems or mental fatigue may ensue. The reason for this dysfunction may be a continuing inflammatory state or damage to brain tissue caused by the abscess. The investigators will evaluate these possibilities with the use of \[18F\]deoxyglucose-positron emission tomography (FDG-PET) and electroencephalography (EEG) in patients who have been treated for brain abscess and who experience cognitive problems and/or fatigue. FDG-PET may identify both inflammation and altered neuronal activity (the latter indicating damage to brain tissue), and EEG may identify altered neuronal activity, including changes in neuronal network activity.

The investigators aim to determine if oral antibiotics are clinically acceptable as treatment of brain abscess. Following 2 weeks of standard intravenous antibiotic therapy, half of patients will continue with this treatment for another 4 weeks or longer while the other half will be assigned to oral antibiotics for the remaining duration of treatment.

The purpose of this European, multicentric, prospective, non-interventional study is to document and evaluate the efficacy and safety of the treatment of severely infected patients with intravenously administered fosfomycin, including patients with osteomyelitis, complicated urinary tract infection, nosocomial lower respiratory tract infection, bacterial meningitis/central nervous system infection, bacteraemia/sepsis, skin and soft tissue infection, endocarditis or other infections, each as far as covered by the respective nationally relevant SmPC.

The Danish Study Group of Infections of the Brain is a collaboration between all departments of infectious diseases in Denmark. The investigators aim to monitor epidemiological trends in central nervous system (CNS) infections by a prospective registration of clinical characteristics and outcome of all adult (\>17 years of age) patients with community-acquired CNS infections diagnosed and/or treated at departments of infectious diseases in Denmark since 1st of January 2015.