Listeria monocytogenes meningitis in immunocompetent children: A retrospective single-centre study.

Objectives: Listeria monocytogenes meningitis has traditionally been associated with specific vulnerable populations such as newborns, pregnant women, immunosuppressed transplant recipients, and older adults with compromised cell-mediated immunity. Instances involving otherwise healthy children without underlying immunological disorders are infrequently reported and considered unusual. Methods: The medical records, clinical courses, laboratory findings, medical imaging, and responses to treatment of immunocompetent children diagnosed with Listeria monocytogenes meningitis were retrospectively analyzed. Results: The study included seven previously healthy children aged 4 months to 15 years. Common onset symptoms included fever, seizures, vomiting, headache, and altered consciousness. Radiological evaluation revealed signs consistent with cerebral oedema in three patients, based on T2 and fluid-attenuated inversion recovery (FLAIR) hyperintensities and loss of grey-white differentiation, although brain oedema cannot be definitively confirmed without histopathological correlation. In addition, two patients exhibited clinical signs of cranial nerve involvement, specifically abducens nerve palsy. Magnetic resonance imaging demonstrated leptomeningeal contrast in four patients, with one showing brain stem involvement. None had recognized immunodeficiencies. Conclusions: This study underscores the importance of considering Listeria monocytogenes meningitis even in the absence of underlying risk factors.