Central nervous system infections

Below are details of the management of bacterial meningitis, meningitis contact prophylaxis, brain abscess, viral encephalitis and viral meningitis.

Bacterial meningitis

• Symptoms of acute meningitis include:
  • Fever
  • Headache
  • Neck stiffness
  • Photophobia

Always seek urgent advice from infectious diseases / microbiology. Discuss further management with infectious diseases on call at the Queen Elizabeth University Hospital (see Appendix 6 for contact details).

• The investigation of suspected meningitis must include:
  • Cerebrospinal fluid for Gram stain, culture and polymerase chain reaction (PCR) for bacteria and viruses
  • CSF sample to biochemistry for protein / glucose, with a paired serum glucose sample
  • Blood cultures
  • Throat swab
  • Clotted and EDTA blood for bacterial PCR
  • See trakcare order set for meningitis
• Administer IV antibiotic therapy urgently on arrival in hospital and after blood cultures.
• Perform CT scan before lumbar puncture if: age ≥60 years; seizures; reduced GCS or abnormal level of consciousness; CNS signs; immunosuppression.

  N.B. Contraindications to CT scan e.g. coagulopathy - discuss with radiology

• Duration of therapy dependent on aetiology:
  • N. meningitides 5 days
  • S. pneumoniae 10-14 days
  • L. monocytogenes 21 days

Bacterial meningitis

• Age <60 years and Listeria not suspected
• Age ≥60 years or if Listeria meningitis suspected

Meningitis Contact Prophylaxis

• All suspected cases of meningococcal disease are notified to the NHSGGC Board, Public Health Protection Unit (see Appendix 6 for contact details).
• Specialists in Communicable Disease will identify close family and friends of the patient who may require antibiotic prophylaxis.
• This should be given as soon as possible (ideally within 24 hours) after diagnosis of the index case.

• Contact prophylaxis – oral therapy (whenever possible)
• Contact prophylaxis – when oral therapy not appropriate

Brain Abscess

• Perform blood cultures.
• Discuss treatment and duration with neurosurgery and microbiology / infectious diseases unit.

Potential source:

• Sinus (Streptococcus milleri, Pneumococcus, Haemophilus influenzae)
• Middle ear (mixed aerobes and anaerobes)
• Post traumatic (Staphylococcus aureus or mixed infections)
• Blood stream, endocarditis (Staph and Strep species)

• Upper respiratory tract source (sinus and middle ear)
• Post-traumatic or blood stream source

Viral encephalitis

• Encephalitis is inflammation of the parenchyma of the brain. It is often associated with meningitis (meningoencephalitis).
• Symptoms include fever and headache with signs of cerebral involvement - fits, altered level of consciousness, confusion, personality change, focal neurological changes e.g. cranial nerve deficits.
• Herpes Simplex Virus (HSV) is the commonest cause of sporadic viral encephalitis, however in many cases no aetiological agent is identified.
• Treatment should be started with IV aciclovir.
• Perform CT scan before lumbar puncture (LP).
• Send CSF for viral PCR as well as microbiology and biochemistry.
• In the first 72 hours after the onset of HSV encephalitis, CSF PCR may be negative; repeat LP is advised if the diagnosis is suspected.

Duration of treatment for confirmed HSV encephalitis is at least 14 days with a second CSF sample for PCR advised after 14 days of treatment. If the HSV PCR remains positive continued treatment is recommended. Discuss with infectious diseases unit / virology.

• Possible viral encephalitis

Viral meningitis

In general no specific antiviral treatment is recommended. Viral meningitis does not require antiviral therapy unless the patient is immunocompromised. Discuss with infectious diseases / virology.

Content last updated December 2018