Brain abscess due to viridans streptococci in a severely immunosuppressed HIV-infected patient.

We report a case of viridans streptococcus brain abscess in a severely immunosuppressed HIV-infected patient with a history of chronic sinusitis. A 39-year-old homosexual man showed mental confusion and worsening of a frontal brain lesion after two weeks with antitoxoplasma therapy. Empiric treatment for central nervous system tuberculosis and pyogenic brain abscess was started. He underwent surgical drainage and the diagnosis of brain abscess due to viridans streptococci was confirmed. All empiric treatments were stopped and ceftriaxone was used for eight weeks, showing complete clinical and radiological resolution. Although infrequent, viridans streptococci, a common pyogenic aetiology of brain abscess in immunocompetent patients, should be considered in the differential diagnosis of brain lesions in AIDS patients.