Listeria meningoencephalitis: two cases and a review of the literature.

INTRODUCTION Although presently uncommon locally, Listeria is increasing an important cause of central nervous system (CNS) infection worldwide. It differs from the common meningitis pathogens in its clinical features and treatment. CLINICAL PICTURE We present 2 recently encountered cases of Listeria meningoencephalitis. In case 1, a previously healthy 42-year-old man presented with clinical features of meningoencephalitis. In case 2, a 64-year-old woman had clinical features of pneumonia and meningoencephalitis. Both had a predominantly lymphocytic picture in their cerebrospinal fluid (CSF) samples. Listeria grew in blood cultures of both patients and the CSF culture of the first. TREATMENT In both cases, Listeria was resistant to the empirical antibiotics used. Intravenous ampicillin was eventually used in both patients, with gentamicin, added for synergistic action in the first. OUTCOME The first patient developed complications of hydrocephalus, subdural collection and extensive cerebritis and ventriculitis. The second patient had focal seizures and a pontine infarct. Both did not survive. CONCLUSION These 2 recent cases with different presentations of intracranial listerosis highlight the increasing importance of listerial infections in Singapore. Clinicians need to be familiar with the features of this lethal disease in order to recognize and manage it successfully.