Overview Pathogens That Cause Meningitis by Age Group Newborns (0-6 mo) Children (> 6 months - < 6 years) Adults (18 - 40 years) Seniors (40 - 65 years) IC AC GBS E. coli Listeria monocytogenes S. pneumoniae N. meningitidis H. influenzae Enteroviruses (coxsackievirus, poliovirus, echovirus) S. pneumoniae N. meningitidis HSV-1 HSV-2 Enteroviruses (coxsackievirus, poliovirus, echovirus) S. pneumoniae Listeria monocytogenes S. pneumoniae Listeria monocytogenes N. meningitidis CMV JC virus Cryptococcus neoformans Toxoplasma gondi (brain abscess) Enteroviruses (coxsackievirus, poliovirus, echovirus) HSV-1 HSV-2 Naegleria fowleri Cryptococcus neoformans West Nile Virus LCMV Definitions meningitis inflammation of the meninges bacterial meningitis can be life-threatening remember: encephalitis is inflammation of the brain parenchyma aseptic meningitis ("sterile meningitis") meningitis caused by organisms other than bacteria majoriy due to viruses enteroviruses are the most common viral cause Clinical presentation fever, headache, altered mental status, neck stiffness there may be variations in clinical presentation due to the type of pathogen, patient age, host immune status Bacterial causes of meningitis by age < 1 month Group B streptococcus (GBS), E. coli, L. monocytogenes prominent causes of meningitis in neonates GBS and E. coli are most common ≥ 3 month - < 10 years S. pneumoniae and N. meningitidis are common H. influenze type B incidence decrease since HiB vaccine introduction in 1980s ≥ 10 years - 34 years S. pneumoniae and N. meningitidis are common 18 years - 34 years S. pneumoniae and N. meningitidis are common > 35 years S. pneumoniae is common Meningitis in Immunocompromised (IC) S. pneumoniae and L. monocytogenes are common Aseptic meningitis more common than bacterial can occur at all ages more common in children summer months Herpes simplex virus (HSV) HSV-1 more associated with encephalitis HSV-2 more associated with meningitis See also "Meningitis" Treatment drug choice depends on what is the most likely pathogen causing meningitis 0 - 28 day old IV ampicillin + cefotaxime or an aminoglycoside (i.e., gentamicin, tobramycin) ≥ 1 month old IV vancomycin + cefotaxime or ceftriaxone if you suspect L. monocytogenes, add ampicillin adults IV vancomycin + cefotaxime or ceftriaxone If > 50 years old, add ampicillin Abbreviations IC = immunocompromised AC = aseptic causes blue = common pathogen in chart