Causes of Bacterial Meningitis by Patient Age
Age Group | Bacteria |
|---|---|
Neonates and young infants | Group B streptococci, particularly Streptococcus agalactiae Escherichia (E.) coli Listeria monocytogenes |
Older infants, children, and young adults | Neisseria meningitidis Streptococcus pneumoniae Staphylococcus aureus* Haemophilus influenzae (rare in developed countries but still seen in countries where the H. influenzae type B vaccine is not widely used) |
Middle-aged adults | S. pneumoniae S. aureus* N. meningitidis (less common in this age group) |
Older adults | S. pneumoniae S. aureus* L. monocytogenes Gram-negative bacteria |
* S. aureus occasionally causes severe meningitis in patients of all ages. It is the most common cause of meningitis that develops after a penetrating head wound. | |