A Rare Case of Slowly Progressive Meningitis Caused by Streptococcus intermedius.

This report describes a case of Streptococcus intermedius meningitis with an unusually gradual clinical course in an elderly patient with cancer. Such a subacute-to-chronic presentation has not been reported previously. Although S. intermedius meningitis typically involves intracranial suppuration, systemic imaging has revealed no abscesses or other infectious foci. The identification of this pathogen can be challenging in some clinical settings. In this patient, S. intermedius bacteremia was confirmed, whereas cerebrospinal fluid cultures were negative. However, a 16S rRNA gene analysis successfully identified S. intermedius in the cerebrospinal fluid. This case highlights the broad clinical manifestations of this reemerging pathogen and supports the utility of molecular diagnostic methods.