Meningitis caused by Streptococcus in adults.

Meningitis caused by Streptococcus is uncommon in adults. Otitis media, mastoiditis, sinusitis, or trauma has antedated most cases reported in the past. Data on 10 recent cases suggest changes in the current pathogenesis of streptococcal meningitis in adults and emphasize the importance of accurate streptococcal speciation. Endocarditis was present in five cases; trauma played a role in two others. Brain abscess, corticosteroids, alcoholic cirrhosis, and peritonitis secondary to chronic peritoneal dialysis were etiologic factors in five patients. Otitis media, mastoiditis, and sinusitis were conspicuously absent. Streptococcus agalctiae accounted for purulent meningitis in two postmenopausal women. Both strains of group B Streptococcus were bacitracin-sensitive and were thus mislabeled group A. Recognition of Streptococcus bovis spared two patients unnecessary aminoglycoside adminstration. Nine of the 10 patients survived, including a women with prosthetic mitral valve endocarditis and a man with a ruptured brain abscess. Differentiation of these streptococci from Streptococcus pneumoniae was seldon possible on the basis of the spinal fluid gram stain alone.