Enterococcal meningitis: report of four cases and review.

Enterococci, a significant cause of human infections outside of the CNS, have only rarely been documented to cause meningitis. To add to our understanding of this uncommon infectious process, we report our experience with four patients with enterococcal meningitis and summarize findings associated with 28 additional cases found in the medical literature. The majority of the adult patients with this condition had coexistent chronic underlying illnesses and were frequently exposed to immunosuppressive therapy. In addition, more than one-third of these patients had experienced CNS trauma or surgery, and 31% had an infection with enterococci at a site other than the CNS. Pediatric patients predominantly had underlying CNS pathology primarily consisting of neural tube defects or hydrocephalus. Primary meningitis occurred in 25% of pediatric patients, with most of these episodes occurring in neonates. Most patients presented with expected signs, symptoms, and physical features of acute bacterial meningitis and had typical CSF abnormalities, including leukocytic pleocytosis, elevated protein levels, and hypoglycorrhachia. The overall mortality rate among patients with enterococcal meningitis was 13%. The small number of patients in this review failed to demonstrate a definite difference in mortality among patients treated with cell wall-active agents alone vs. those treated with combination therapy with an aminoglycoside, although studies of patients with other complicated enterococcal infections suggest that combination therapy would be preferable.