- In most cases, the infection causing meningitis arises in the nasopharynx:
- Can lead to intravascular invasion and bacteraemia
- Meningeal invasion occurs at high-level bacteraemia following penetration of the blood-brain barrier
- Bacteria associated with meningitis express antiphagocytic capsular polysaccharide that enables survival/multiplication within the blood
- Direct (non-haematogenous) spread from contiguous structures less common
- May occur in fractures, sinusitis or post-surgery
