Fatal bacterial CNS infections: a systematic review and a forensic case report

Central nervous system (CNS) infections may cause sudden unexpected death when diagnosis is delayed or missed. We report a fatal case of Streptococcus pyogenes meningoencephalitis and systematically review postmortem investigations of fatal bacterial CNS infections. A 57-year-old woman was found dead at home after untreated otalgia, hearing loss, purulent otorrhea, low-grade fever, asthenia, and vomiting. Autopsy showed diffuse cerebral edema, subdural empyema involving the posterior fossa, and cerebellar tonsillar herniation. Histology demonstrated acute suppurative meningoencephalitis with vasculitic injury. Streptococcus pyogenes was isolated from purulent material collected from the empyema; toxicological analyses were negative. The systematic review followed PRISMA 2020. PubMed/MEDLINE and Scopus were searched from database inception to 22 August 2026. Sixty-two studies describing 68 fatal bacterial CNS infections were included. The included cases showed a broad spectrum of postmortem-confirmed bacterial infections, including meningitis, meningoencephalitis, ventriculitis, brain abscess, subdural empyema, rhombencephalitis, spinal meningeal involvement, and infectious vascular complications. Postmortem pathogen-directed testing included culture, histochemical stains, antigen detection, immunohistochemistry, PCR, sequencing, MALDI-TOF identification, or equivalent methods. Autopsy remains central to diagnosing fatal bacterial CNS infections. Integration of neuropathology with postmortem pathogen-directed testing improves pathogen identification, cause-of-death determination, reconstruction of the route and mechanism of death, and infectious disease surveillance.