What are the bacteria commonly responsible for bacterial meningitis?

Causative bacteria for meningitis varies according to age:

Neonates
  • Streptococcus agalactiae (Group B)
  • Gram –ve bacilli (e.g. E. coli, Klebsiella, Haemophilus influenzae)
  • Listeria Monocytogenes
Children 1-24 months
  • Neisseria Meningitidis
  • Streptococcus pneumonia
  • Streptococcus agalactiae (Group B)
  • Haemophilus influenza
Older Children & Younger Adults
  • Neisseria Meningitidis (22%)
  • Streptococcus pneumonia (18%)
  • Staphylococcus Aureus (10%)
Older Adults
  • As for younger adults
  • Listeria Monocytogenes
  • Aerobic gram-negative bacilli
  • Significant change in aetiology has occurred over recent years due to UK vaccination programmes:
  • Incidence of Haemophilus influenzae Type b, serogroup C meningococcus and pneumococcal disease is reducing
  • Serogroup B meningococcus is the most common cause in children aged three months or older as there is currently no vaccine available