Central nervous system infections

In addition to the NHSGGC poster, see below for further information on bacterial meningitis and viral encephalitis. Guidance not covered by the NHSGGC poster includes management of brain abscess and meningitis contact prophylaxis and can be found below. 

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 via switchboard at the Queen Elizabeth University Hospital.

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 (LP) 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

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, which 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 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.

Content last updated January 2021