Disease modifying treatment available:
Time critical diagnosis and management:
Lateralising:
None
| Subclassifications | Epidemiology | Clinical features |
|---|---|---|
| Acute bacterial meningitis | None | |
| Chronic bacterial meningitis | None |
The organisms that cause bacterial meningitis in an individual vary on their age and immune status. Neisseria meningitidis, Streptococcus pneumonia and Haemophilus influenzae type B are the most common causative agents in adults.
In neonates group B strep, E. coli, S. pneumonia and L. monocytogenes are common pathogens.
Listeria monocytogenes also causes disease in older people.
The prevalence and organisms responsible for causing bacterial meningitis has changed markedly in the UK following the introduction of vaccination for H. influenzae type B and certain strains of meningococcus.
None
Bacterial meningitis may cause the following:
The antibiotic choices outlined below are based on management guidelines from UK joint specialist societies guideline (%cite18).
Start antibiotics as early as possible. Ceftriaxone 2g IV BD is commonly used. In patients over 55 years old add amoxicillin 2g IV QDS to cover listeria.
The addition of IV vancomycin 15–20 mg/kg bd should be considered in those who have recently travelled outside the UK or in those who have been exposed to multiple courses of antibiotics. Rifampicin 600 mg BD is an alternative.
If there is sinusitis, mastoiditis or otitis the chance of anaerobic infection is greater. An antibiotic with good anaerobic cover such as metronidazole may be added.
Chloramphenicol 25 mg/kg 6 hourly is an alternative for those with severe penicillin allergy. If listeria cover is required co-trimoxazole should be added at 10–20 mg/kg (of the trimethoprim component) in four divided doses.
Dexamethasone 10mg 6 hourly i.v. or oral for 4 days if pneumococcal meningitis likely (eg no purpuric rash) and it can be started before or at same time as antibiotics. NICE advise steroids should be given before antibiotics if possible and that there is no value if administration is more than 12 hours after antibiotics are given.
The first trial providing good evidence for the use of dexamethasone in bacterial meningitis showed improved morbidity and mortality (%cite15). A further study has demonstrated improvement in mortality in pneumococcal meningitis following the use of dexamethasone (%cite16). Subgroup analysis suggests the benefit seen in those with pneumococcal meningitis. A study specifically of meningococcal meningitis did not show a statistically significant benefit with respect to disability, deafness or death, but also did not provide any evidence of increased adverse events in the dexamethasone treated group (%cite17).
Bacterial meningitis is a notifiable disease. Public health authorities should be contacted and contacts traced - it may be necessary to offer prophylaxis.
In Scotland, pneumococcal vaccination is offered to those aged 65 and over or those with significant medical co-morbidities.
Infectious disease specialists will provide useful input.
Those with recurrent meningitis or atypical organisms should be investigated for complement deficiency and referral to an immunology specialist in such cases should be considered.
In those with a history of recent neurosurgery or rhinorrhoea or otorrhoea CSF leak should be sought.
All adults with meningitis should be offered an HIV test.
If 'sepsis of unknown origin' cover is given is the CNS covered?
What can be added to CNS cover to broaden to 'sepsis of unknown origin'?
What antibiotics can be given if there is penicillin allergy?
What factors contribute to poor outcome in bacterial meningitis?
Can resistant organisms be rapidly identified on PCR?
Are there serum biomarkers of CSF infection which can be used in cases where it is uncertain if LP is required?
How long after an LP does it take meningeal enhancement to resolve?
Do cervical or suboccipital punctures increase diagnostic yield in a clinically useful way and are they more dangerous?