Encephalitis and meningitis

Red flags

Consider urgent referral for patients with the following:

Suspicion of encephalitis/meningitis should prompt urgent transfer to Emergency
Flu like symptoms associated with
- Headache
- Confusion
- Seizures
- Altered movement or sensation
- Diplopia
- Dysarthria, dysphasia
- Petechial rash

Encephalitis/meningitis is an inflammation of the brain or meninges most commonly caused by viral infection or bacterial infection. Encephalitis can be mild and self-limiting but can also be a rapidly progressive and potentially life threatening condition and all patients suspected of having this diagnosis with any red flags should be transferred urgently to Emergency.

Suspected meningitis cases should always be transferred urgently to Emergency. Most cases are likely to be managed by Neurology, General Medicine or Infectious Diseases after initial treatment in Emergency.

Other important information for referring practitioners

Medical management

Encephalitis
- Symptoms are mild and stable the patient can be managed symptomatically
- If managing the patient conservatively make sure that information regarding red flags is made clear to the patient. Also consider urgent referral if the patient is not able to be supervised in case of sudden deterioration.
Meningitis
There are many causes of meningitis. These are:
- Viral
  - Enterovirus
  - Herpes simplex
  - Mumps
  - HIV
  - West Nile virus
- Bacterial
  - Steptococcus pneumonia
  - Neisseria meningitidis
  - Haemophilus influenzae
  - Listeria monocytogenes
- Amoebic
- Fungal
  - Cryptococcus neoformans (may have a more chronic presentation)

All suspected cases of bacterial meningitis should be immediately transferred to hospital after the administration of iv/im antibiotics as follows:
- Ceftriaxone iv/im or Cefotaxime is first choice, if not available give:- benzyl penicillin as below:
  - Benzyl penicillin 60mg/kg (for all ages) iv (give im if unable to gain access to iv route)
  - If anaphylactic allergy to penicillin exists arrange immediate transfer to hospital but do not administer a cephalosporin
- If possible, collect a specimen of blood for cultures prior to administration of the antibiotic but this should not delay patient transfer to hospital
- All close contacts of the patient (if proven to be meningococcal disease) should be offered prophylactic treatment
  - Adults give rifampicin 10mg/kg orally 12 hourly (max 600mg) for 2 days
  - Infants (over 1 month old) and children give Rifampicin 10mg/kg orally 12 hourly for 2 days
  - Infants less than 1 month old give rifampicin 5mg/kg 12 hourly for 2 days
  - In pregnancy or if rifampicin is contraindicated give Ceftriaxone 125mg (<12 yrs), 250mg (12 yrs and over) im as single dose
- Vaccination is also now available for Meningococcal B as well as C infections