Adults with meningitis caused by viridans streptococci

Background: We analyzed the clinical features and therapeutic outcomes of adults with meningitis caused by viridans streptococci. Patients and Methods: 12 adult patients with meningitis caused by viridans streptococci were enrolled in this study. Clinical data were collected over a period of 15 years. Results: Of the 12 patients, 11 patients had community-acquired meningitis, while one had nosocomially acquired meningitis. 11 contracted the spontaneous form and one contracted the postneurosurgical form. ALL isolates were susceptible to penicillin. The portals of entry of infection were determined in all 12 patients; five patients had otopharyngeal infections with or without their being spread hematogenously. The infections in six patients were spread hematogenously, but one of them was spread hematogenously with endocarditis. One patient became infected after a craniotomy. The patients infected by viridans streptococci had a high incidence of focal suppuration and cerebral vasculitis but no deaths occurred. Conclusion: Adult bacterial meningitis caused by viridans streptococci is not uncommon and otopharyngeal infection appears to be an important portal of entry. Clinical manifestations varied according to the different underlying conditions. The results of this study also demonstrate the high incidence of intracranial focal suppuration and cerebral vasculitis concomitant with meningitis. Penicillin remains the treatment of choice for patients with meningitis caused by viridans streptococci. Therapeutic outcome is favorable for patients who receive prompt treatment.