Clinical Presentations and Nosocomial Infections of Neurolisteriosis.

Neurolisteriosis is a listerial invasive disease, which is characterized by brain parenchymal and meningeal involvement, with a high fatality rate and frequent neurological sequelae. The main clinical presentations of neurolisteriosis are meningitis, meningoencephalitis, rhombencephalitis, and brain abscess. Neuroradiological imaging is useful to distinguish these clinical presentations. The diagnosis of neurolisteriosis may be confirmed by cerebrospinal fluid or blood cultures, but these tests may have different yields depending on the clinical presentation of neurolisteriosis. The elderly and immunocompromised patients are the most susceptible population to developing neurolisteriosis, and few cases occur in healthy young people. This disease is caused by Listeria monocytogenes, a foodborne pathogen with an intracellular life cycle, which can be found in processed foods, and it remains the third cause of bacterial meningitis in adults. Most cases of neurolisteriosis are community-acquired, but several hospital-acquired cases and outbreaks have been reported in the literature and linked to the consumption of food served to inpatients. Aminopenicillins are the antibiotics with the highest impact on the prognosis of neurolisteriosis, and alternative antimicrobial therapies must be considered in those cases where a first-choice antibiotic cannot be administered or with antibiotic treatment failure. In this article, the epidemiology, sources of infection, pathogenesis, and clinical aspects of neurolisteriosis are reviewed, highlighting the main clinical presentations of the disease. Relevant information regarding hospital-acquired neurolisteriosis is also included to provide a framework for discussing nosocomial cases definition.