Primary Care Guidelines
Immediate Management
Top priority: transfer immediately to the hospital as an emergency.
Recommendations regarding antibiotic therapy before transfer:
- DO NOT delay transfer to hospital to give antibiotics
- Only if there is likely to be a clinically significant delay in transfer: give IV / IM ceftriaxone or benzylpenicillin outside of hospital
Penicillin allergy:
- If the patient has a severe allergy (e.g. anaphylaxis, angioedema, respiratory distress) → do NOT give antibiotics outside of hospital
- If the patient has a non-severe allergy → cefrriaxone or benzylpenicillin can be given
Prevention of Secondary Cases
Antibacterial prophylaxis is aimed at eliminating asymptomatic carriage of Neisseria meningitidis from close contacts of the index case, thereby reducing onward transmission and secondary cases
Indication
Irrespective of vaccination status, the following should be offered antibacterial prophylaxis
- Contact with the index case in a household type setting during the 7 days before onset of illness.
- Sexual or other intimate contact during the 7 days before onset of illness.
- Direct exposure to large particle droplets or secretions from the respiratory tract
Antibacterial Prophylaxis
- Ciprofloxacin (alternative or recent travel to Middle East or Asia: rifampicin)
- Also consider vaccination against Neisseria meningitidis
Secondary Care Guidelines
Investigation and Diagnosis
Tests
Ideally, perform the following tests before starting antibiotics:
- Bacterial throat swab for meningococcal culture
- Blood tests
- Blood culture
- White blood cell count
- CRP
- Blood glucose
- Whole-blood PCR (including meningococcal and pneumococcal)
- HIV test
Lumbar puncture
Do not perform lumbar puncture if ANY of the following:
- Extensive / rapidly spreading purpura
- Infection at lumbar puncture site
- Risk factors for an evolving space-occupying lesion
- Signs of raised ICPIntracranial pressure, any of the following:
- Focal neurological features (including seizures or posturing)
- Abnormal pupillary reactions
- GCS ≤9, or a progressive and sustained or rapid fall in level of consciousness
Based on the presence or absence of contraindications against a lumbar puncture, there are 2 possible pathways:
| No contraindications | Gold standard diagnostic pathway of meningitis:
|
| Yes contraindications |
|
Lumbar puncture is the confirmatory test of choice for meningitis and allows assessment of the underlying cause.
CSF Analysis in Meningitis
| Parameter | Bacterial | Viral | TB | Fungal |
|---|---|---|---|---|
| Opening pressure | ↑ | – / ↑ | ↑ | ↑ |
| Appearance | Turbid | Clear | Slightly turbid | Clear/turbid |
| WCC | ↑↑ (neutrophils) | ↑ (lymphocytes) | ↑ (lymphocytes) | ↑ (lymphocytes) |
| Glucose | ↓ | – | ↓ | ↓ |
| Protein | ↑ | – / ↑ | ↑↑ | ↑ |
| Gram stain / culture | Often +ve | – | Ziehl-Neelsen stain (may be +ve) | India ink (may be +ve) |
In addition to the parameters listed above, PCR for relative pathogens should be performed as well.
Neuroimaging
Do not routinely perform neuroimaging before lumbar puncture.
Only perform neuroimaging if ANY of the following (NB these overlap with some reasons not to perform lumbar puncture):
- Risk factors for an evolving space-occupying lesion
- Signs of raised ICPIntracranial pressure, any of the following:
- Focal neurological features (including seizures or posturing)
- Abnormal pupillary reactions
- GCS ≤9, or a progressive and sustained or rapid fall in level of consciousness
If neuroimaging reveals features of space-occupying lesion or signs of raised ICP → DO NOT perform a lumbar puncture
Since neuroimaging takes time to perform and to be reported, management in these patients should be
- 1) Take other microbiology samples (i.e. throat swab and blood cultures and PCR), if haven’t and then
- 2) Give antibiotics immediately
- 3) Stabilise the patient then perform neuroimaging
Hospital Management (Bacterial Meningitis)
IV antibiotic is the top priority in bacterial meningitis, it should be started ASAP, and within 1 hour of arriving at hospital
Ideally take microbiology samples (esp. blood cultures – this should be always done)and lumbar puncture (not always done – see above) before, then give antibiotics immediately (if safe to do so and will not cause a clinically significant delay to start antibiotics)
Initial Management (Unknown Organisms)
There are 2 main aspects of initial management:
Empirical Antibiotic Therapy
Offer:
- Ceftriaxone (alternative: cefotaxime)
- AND amoxicillin only if there are risk factors for Listeria monocytogenes (very young children / >60 y/o / pregnancy / immunosuppression / diabetes / alcohol misuse / cancer / kidney or liver disease)
Do not routinely give intravenous aciclovir unless herpes simplex encephalitis is strongly suspected
Ceftriaxone / cefotaxime can be used as long as there is a non-severe allergy to beta-lactams.
If there is a severe allergy (e.g. anaphylaxis, angioedema, respiratory distress), the BNF recommends considering chloramphenicol and seeking specialist advice.
Disclaimer: the exact wording of NICE is to add amoxicillin if there are ‘risk factors for Listeria monocytogenes’, however, these are not specifically defined.
The above-listed risk factors were instead listed in the BNF treatment summary.
Corticosteroid Therapy
IV dexamethasone should also be given with or before first dose of antibiotic if >3 m/oIf younger than 3 months but with strongly suspected / confirmed bacterial meningitis, seek advice from infection specialist on giving dexamethasone and bacterial meningitis is strongly suspected or confirmed
- Do not give dexamethasone in meningococcal disease
- Do not delay antibiotics to wait for dexamethasone to be started
- Only continue dexamethasone if meningitis is found caused by pneumococcus or Haemophilus influenzae type b
Antibiotic Choice in Known Organisms
NICE guideline covered the choice of antibiotics for 6 organisms, but there are actually only 2 antibiotic regimens one needs to learn:
- In terms of the guidelines, there are some discrepancy regarding duration to continue the antibiotic, but the author deems it excessive and is unlikely to be important for exams.
- Clinically, the choice of antibiotic would be guided by local microbiology guidelines and culture sensitivities
| Causative organism | 1st line antibiotic | 2nd line antibiotic | Severe penicillin allergy* |
|---|---|---|---|
| Neisseria meningitidis (including meningococcal disease) | Ceftriaxone | Cefotaxime | Chloramphenicol |
| Streptococcus pneumoniae | |||
| Haemophilus influenzae type b | |||
| Group B streptococcus | |||
| Enterobacterales (coliforms) | |||
| Listeria monocytogenes | Amoxicillin / ampicillin | Co-trimoxazole | Chloramphenicoil + co-trimoxazole |
| *NICE recommends considering the same penicillin-containing antibiotics if the reaction was not a severe allergy. | |||
The mainstay of treatment of viral meningitis is supportive careincluding hydration, analgesia, and antipyretics.[ref]
Antibiotics / Antivirals are not routinely indicated, since most cases (e.g. enteroviral) are self-limiting.
Do NOT confuse viral meningitis with viral encephalitis — in suspected encephalitis, IV aciclovir should be started empirically to cover HSV/VZV. In suspected meningitis, empirical IV antibiotics (+- corticosteroids) should be started immediately, before results (e.g., CSF analysis/blood cultures) are available:
- Bacterial cause: continue/switch antibiotic therapy depending on causative organism
- Viral cause: discontinue empirical antibiotic therapy / corticosteroids & continue supportive therapy
References
NICE guideline Meningitis (bacterial) and meningococcal disease: recognition, diagnosis and management
NICE BNF Treatment summaries Central nervous system infections, antibacterial therapy
NICE BNF Treatment summaries Antibacterials, use for prophylaxis Meningococcal disease: prevention of secondary cases