Rare but serious inflammation of the meninges caused by various bacteria. Streptococcus pneumoniae, Haemophilus influenzae type b (Hib), and Neisseria meningitidis are the predominant causative pathogens, in both adults and children.
Most commonly affects extremes of age (<5 years and >60 years) because of impaired or waning immunity.
Overall incidence of bacterial meningitis has fallen in developed countries because of the widespread use of pneumococcal and Hib vaccines. S pneumoniae is the most common cause of bacterial meningitis in the US and many countries worldwide.
An LP to obtain CSF is the most important investigation when a diagnosis of bacterial meningitis is considered.
Empiric antimicrobial therapy should be started promptly. When the specific organism is identified, treatment can be modified accordingly.
Hearing should be tested before discharge or within 4 weeks after discharge in all children with bacterial meningitis to detect any hearing loss as early as possible.
Ventral view of human brain showing purulent basilar meningitis infection due to Streptococcus pneumoniae
Image provided by the CDC Public Health Image Library