Meningitis

Meningitis is inflammation of the membranes (called meninges) surrounding the brain and the spinal cord. It is usually caused by an infection. Meningitis must be treated as an emergency as it can be a life-threatening illness. If diagnosed and treated quickly, a full recovery can usually be expected.

Symptoms of meningitis

Meningitis symptoms include:

  • severe headache;
  • fever;
  • stiffness of the neck and back muscles (which is often not reported early in the course of the illness);
  • photophobia (abnormal sensitivity or intolerance to light);
  • irritability;
  • confusion;
  • nausea and vomiting;
  • lethargy or drowsiness;
  • muscle and joint pains; and
  • seizures.

Other signs may include a rash, as seen in meningococcal disease. The rash appears as red or purple dots or bruises that usually don’t disappear or fade when pressure is applied.

In infants and small children symptoms may be very non-specific, and include:

  • fever;
  • irritability;
  • inactivity or floppiness;
  • feeding problems;
  • very high-pitched or unusual crying; and
  • a bulging fontanelle (soft spot on top of the head).

Complications of meningitis

Bacterial meningitis (particularly meningococcal meningitis) can occur together with septicaemia (blood poisoning). Meningococcal septicaemia is a very serious condition that can result in organ failure, gangrene of the extremities (e.g. fingers or toes) and death.

Potential long-term complications of meningitis may include:

  • hearing impairment; and
  • brain damage, which can result in seizures, learning difficulties and/or physical impairment.

Causes

Meningitis can be caused by a viral or bacterial infection or, less commonly, a fungal or parasitic infection. Viral and bacterial infections usually spread via close contact through sneezing, coughing, kissing and sharing personal items.

Bacterial meningitis can be associated with other bacterial infections such as sinusitis or pneumonia. Sometimes the bacteria causing meningitis may have been living harmlessly in the body for a long time before causing the illness.

Fungal meningitis tends to be more common in people with weakened immune systems.

Other rare, non-infective causes of meningitis include:

  • malignancy (cancer);
  • certain inflammatory conditions (such as systemic lupus erythematosus and sarcoidosis); and
  • reactions to certain medicines.

Types of meningitis

Meningitis types
Aseptic meningitisthis is an inflammation that is not caused by bacterial infection. Viruses are the most common cause of aseptic meningitis but there are other causes such as systemic lupus erythematosus (SLE), sarcoidosis, Behcet’s disease and reactions to some types of medicines.
Bacterial meningitisthis is an inflammation of the meninges that is caused by a bacterial infection. The most common causes of bacterial meningitis are infections with Neisseria meningitidis and Streptococcus pneumonia. Other bacterial causes include Haemophilus influenza type b (Hib), Listeria monocytogenes, Group B streptococcus and Escherichia coli.
Cryptococcal meningitisthis type of inflammation of the meninges is caused by infection from a type of yeast called Cryptococcus, which is commonly found in soil and bird droppings. Cryptococcal meningitis resulting from Cryptococcus neoformans infection most often affects people with weakened immune systems, such as those with HIV/AIDS.
Infectious meningitisthis is meningitis caused by infection with bacteria, viruses, fungi or parasites.
Meningococcal meningitisinflammation of the meninges due to an infection with a type of bacteria called Neisseria meningitidis (meningococcus). This is an extremely dangerous type of meningitis as it can progress rapidly, and is highly contagious. Adolescents and young adults are most commonly affected.
Neoplastic meningitisinflammation of the meninges that is caused by malignant (cancer) cells.
Viral meningitisinflammation of the meninges caused by a virus, commonly one of the enteroviruses. Other viruses that can cause meningitis include mumps, herpes simplex virus and HIV. Viral meningitis occurs frequently in children. The symptoms are similar to bacterial meningitis, but it is usually less severe.
Tuberculous meningitis inflammation of the meninges caused by tuberculosis infection (rare in Australia). This is very dangerous and if left untreated may cause brain damage.
Syphilitic meningitis inflammation of the meninges due to infection with the bacterium that causes syphilis. Some people with untreated syphilis who are in the tertiary stage develop a form of meningitis.
Lymphocytic choriomeningitis meningitis that is caused by infection with a rodent-borne virus known as lymphocytic choriomeningitis virus (LCMV). The primary host of the virus is the common house mouse but other rodents, including pets, can be infected. Humans become infected through exposure to fresh urine, droppings, saliva or nesting materials.

Risk factors

Your risk of meningitis is increased if you:

  • are not up-to-date with your routine vaccinations;
  • have a weakened immune system as a result of illness or certain medicines; or
  • have recently had a head injury, neurosurgery or spinal surgery.

Factors that may increase your risk of developing meningococcal disease include:

  • having recently been unwell;
  • exposure to smokers;
  • living in crowded conditions (e.g. boarding school or college); and
  • having multiple intimate kissing partners.

Diagnosis

If a diagnosis of meningitis is suspected based on your symptoms and physical examination, a lumbar puncture (also known as a spinal tap) may be performed to confirm the diagnosis. A lumbar puncture is a procedure where a small sample of cerebrospinal fluid (CSF) – the fluid that surrounds your brain and spinal cord – is taken and tested for signs of infection and inflammation. A lumbar puncture can help confirm the cause of meningitis.

Sometimes a CT scan of the brain may be necessary to test for swelling or pressure on the brain, or complications from meningitis.

Blood tests and tests of any skin lesions (for meningococcal disease) are usually also performed to help determine the extent and cause of the infection.

Treatment

Meningitis requires immediate hospital treatment as it can be a serious, life-threatening illness.

Bacterial meningitis

Bacterial meningitis requires prompt treatment with antibiotics. Corticosteroid medicine is usually given as well, to reduce the risk of complications, including seizures and brain swelling.

Viral meningitis

Viral meningitis usually gets better on its own with rest and plenty of fluids. Headache and fevers can be treated with pain-relievers.

Fungal meningitis

Fungal meningitis is treated with anti-fungal medicines.

Non-infectious causes of meningitis

Treatment will depend on the underlying cause.

Prevention

There are several vaccines that can help prevent infection with viruses and bacteria that are known causes of meningitis.

The following vaccines are available and part of the National Immunisation Program Schedule.

  • Pneumococcal conjugate (13vPCV) vaccine and pneumococcal polysaccharide (23vPPV) vaccine – these vaccines protect against various strains of pneumococcal disease.
  • Haemophilus influenzae type b (Hib) vaccine – cases of Haemophilus influenzae type b meningitis have dramatically declined since the introduction of this vaccine.
  • Meningococcal vaccines. There are several different serogroups, or strains, of meningococci – those that most commonly cause disease are groups A, B, C, W and Y. Meningococcal C vaccine protects against infection with Neisseria meningitidis group C. The number of cases of group C meningococcal disease has significantly declined since introduction of this vaccine. There is also a vaccine against groups A, C, W and Y, but this vaccine is only recommended in certain circumstances and is not available on the National Immunisation Program Schedule. A vaccine against group B meningococcus, which is the most common cause of meningococcal disease in Australia, has recently been approved for use in Australia, but is not yet available on the National Immunisation Program Schedule.
  • Measles, mumps, rubella and varicella (chickenpox) (MMRV) vaccine. Measles, mumps and varicella can cause meningitis, so immunisation against these illnesses is important to protect yourself and your children.

If you have been exposed to someone with meningococcal disease, it may be recommended that you take a course of antibiotics to prevent infection. Usually only people who have been in close contact with the infected person will need to take antibiotics. Check with your doctor if you are concerned.

Last Reviewed: 11 February 2014
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References

1. Meningitis (revised June 2010). In: eTG complete. Melbourne: Therapeutic Guidelines Limited; 2013 Jul. http://online.tg.org.au/complete/ (accessed Oct 2013).
2. Australian Government Department of Health and Ageing. The Australian Immunisation Handbook, 10th Edition 2013. 4.10 Meningococcal disease (updated 13 Mar 2013). http://www.immunise.health.gov.au/internet/immunise/publishing.nsf/Content/handbook10-4-10 (accessed Oct 2013).
3. Australian Government Department of Health and Ageing. The Australian Immunisation Handbook, 10th Edition 2013. 4.3 Haemophilus influenzae type b (updated 13 Mar 2013). http://www.immunise.health.gov.au/internet/immunise/publishing.nsf/Content/handbook10-4-3 (accessed Oct 2013).
4. Centers for Disease Control and Prevention (CDC). Meningitis (updated 19 Mar 2013). http://www.cdc.gov/meningitis/index.html (accessed Oct 2013).
5. Centers for Disease Control and Prevention (CDC). Viral meningitis (updated 15 Mar 2012). http://www.cdc.gov/meningitis/viral.html (accessed Nov 2013).
6. Royal Children’s Hospital Melbourne. Clinical Practice Guidelines – Meningitis/Encephalitis (updated 25 Aug 2013). http://www.rch.org.au/clinicalguide/guideline_index/Meningitis_Guideline/# (accessed Oct 2013).
7. Westmead Children’s Hospital; Sydney Children’s Hospital; Kaleidoscope. Factheet – Meningococcal infection (updated 6 Apr 2010). http://www.sch.edu.au/health/factsheets/joint/?mencoccj.htm (accessed Nov 2013).
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