ABSTRACT
DEFINITION Inflammation of the leptomeninges (pia and arachnoid membranes) caused by bacterial infection.
EPIDEMIOLOGY • Annual incidence: 1.9 per 100 000 for Neisseria menin-
gitidis; 1.6 per 100 000 for Haemophilus influenzae; 1.0 per 100 000 for Streptococcus pneumoniae.
