Central nervous system infection with Listeria monocytogenes

The foodborne pathogen Listeria monocytogenes has a particular tropism for the central nervous system and can produce infection in the meninges and brain substance. Well-recognized clinical syndromes include meningitis, brain abscess, rhombencephalitis, and spinal cord abscess; simultaneous infection of the meninges and brain is common. Although it is an uncommon cause of infection in the population at large, L. monocytogenes is an important cause of central nervous system infection in those with impaired cell-mediated immunity, whether due to underlying disease or treatment with immunosuppressive therapeutic agents; it is the etiology in 20% of bacterial meningitis cases in neonates and in 20% of cases in those older than 50 years. Ampicillin is considered the treatment of choice, and trimethoprim-sulfamethoxazole is recommended for those allergic to penicillin. At-risk patients should be advised to avoid unpasteurized milk and soft cheeses along with deli-style, ready-to-eat prepared meats, particularly poultry products.