STUDIES ON THE PATHOGENESIS OF MENINGITIS. I. INTRATHECAL INFECTION*

Abstract

Meningitis was produced in dogs by instillation of 103 to 106 Diplococ-cus pneumoniae into the subarachnoid space through a small midline burr-hole. Infection, lasting 48 to 96 hours, was characterized by a proges-sive increase in CSF cells in bacteria. There was thrombosis and hemorrhage in a few dogs but in most lesions consisted of an exudative reaction involving meninges of the entire neuraxis as well as ventricular system. There was some correlation between the degree of surface meningitis and number of cells in bacteria in CSF, but no correlation between the amount of exudate in ventricles and cells and bacteria in CSF. Course of infection was not altered by prednisolone given for 5 days before instillation of bacteria. Meningitis in leukopenic animals resulted in few cells in CSF, sparse exudation and longer survival than in normal controls.