First case of Listeria innocua meningitis in a patient on steroids and eternecept

Abstract

Introduction: Listeria innocua is widespread in food and the environment and is considered to be a non‐pathogenic bacterium in healthy subjects. To date, this species has only been associated with human diseases in a fatal case of bacteraemia in an elderly patient. Here, we describe a case of acute meningitis infection caused by this bacterium. Case presentation: Our patient had an increased risk of infection because of treatment with etanercept and a corticosteroid given for rheumatoid arthritis. Etanercept use has been described previously as the possible cause of multiple Listeria monocytogenes infections (to date, four cases have been described, of which two were cases of arthritis and two of meningitis), but etanercept has never been associated with L. innocua meningitis. In our case, despite rapid identification of the pathogen and proper antibiotic treatment, the patient had an unfavourable outcome. Conclusion: To the best of our knowledge, this report constitutes the first documentation of a case of meningitis due to L. innocua, and our experience serves as a warning to microbiologists and clinicians that L. monocytogenes is not the only Listeria sp. that can cause human meningitis.