Bacterial meningitis in adults

Bacterial meningitis represents a life-threatening inflammation of the meninges. Streptococcus pneumoniae, Neisseria meningitidis, and Haemophilus influenzae type b (Hib) are the predominant causative pathogens. 

It most commonly affects adults >60 years because of impaired or waning immunity.

Obtain cerebrospinal fluid by performing a lumbar puncture; this is the most important investigation for suspected bacterial meningitis.

Start empirical antimicrobial therapy promptly. When the specific organism is identified, target treatment accordingly.

Bacterial meningitis is a serious inflammation of the meninges caused by various bacteria. Streptococcus pneumoniae, Neisseria meningitidis and Haemophilus influenzae type b (Hib) are the predominant causative pathogens in adults. 

This topic covers non-meningococcal bacterial meningitis acquired by adults in the community; meningitis may also be associated with invasive procedures or head trauma, but healthcare-associated meningitis is beyond the scope of this topic. For information on meningococcal disease see  Meningococcal disease.