Listerial Meningitis and Brain Abscess With Coexisting COVID-19 Infection in a Young, Immunocompetent Male: A Case Report

Listeria monocytogenes (LM) is a gram-positive intracellular pathogen that can cause central nervous system infections such as meningitis, meningoencephalitis, rhombencephalitis, or cerebritis. It rarely causes a brain abscess. Listerial meningitis and brain abscess most commonly occur in immunocompromised individuals, neonates, pregnant females, alcoholics, and the elderly. We present a unique case of a young immunocompetent male who presented with listerial meningitis and brain abscess. Coexisting coronavirus disease 2019 (COVID-19) infection was also present. Since LM was not included in the differentials, the standard antibiotic regimen started for the meningitis therapy was ineffective. Remdesivir was administered to treat the coexisting COVID-19 infection. When the lumbar tap polymerase chain reaction pointed out that the causative agent was Listeria, we shifted to ampicillin and gentamicin therapy, to which the patient responded very effectively.LM is an atypical cause of meningitis and brain abscesses. A high index of suspicion is therefore required for early detection and effective treatment of listerial meningitis and brain abscess.