Newborn (0-6 months): Group B streptococci, E coli, Listeria

Children (6 months-6 years): S pneumoniae, N meningitidis, H influenzae type B, enteroviruses

6-60 years: S pneumoniae, N meningitidis (#1 in teens), enteroviruses, HSV

>60 years: S pneumoniae, Listeria, gram Θ rods

- Give ceftriaxone and vancomycin empirically (add ampicillin if Listeria is suspected).- Viral causes of meningitis: enteroviruses (especially coxsackievirus), HSV-2 (HSV-1 = encephalitis), HIV, West Nile virus (also causes encephalitis), VZV.- In HIV: Cryptococcus spp.