Meningitis is the inflammation of the meninges (the membrane lining of the brain and spinal cord). It usually refers to infections caused by viruses, bacteria, fungi, and other microorganisms such as parasites. Bacterial meningitis is life threatening and can cause death within hours, if not properly treated. There are many types of meningitis and whilst the symptoms are similar for each, the causes, treatments and outcomes do vary.
Some of the bacteria that cause meningitis can also cause septicaemia an infection of the blood. The toxins released by the bacteria can cause damage to blood vessels and organs throughout the body.
Some people develop meningitis or septicaemia. Other people develop both meningitis and septicaemia at the same time.
The most common bacterial types seen today are meningococcal disease (meningococcal meningitis and/or meningococcal septicaemia) and pneumococcal meningitis. There are various strains of meningococcal meningitis, the most common in Australia being B and C. Antibiotics are still the most effective form of treatment but death does occur in 5% of cases. In addition, about 20% are left with permanent disabilities such as cerebral palsy, limb amputations, learning difficulties and deafness.
In the past, Haemophilus Influenza type b (Hib) meningitis used to be the most common cause of bacterial meningitis and other serious infections like epiglottitis in infants. It has become much less common since the introduction of Hib vaccines.
Some forms of bacterial meningitis affect newborn babies. The most common are E coli, group B streptococcus and Listeria. These types are rare outside of the neonate period. (The neonate period may be defined as the period from birth to approximately 28 days following birth).
Viral meningitis is an uncommon complication of some viral illnesses (eg, herpes). Most cases are mild but more severe illnesses sometimes do occur. It is rarely fatal. No antibiotic treatment or vaccine is available for most viral meningitis.
Amoebic meningitis is well known in hotter states of Australia. Despite its notoriety, amoebic meningitis is a very rare infection. It is caught from stagnant water in waterholes and in poorly chlorinated swimming pools, especially when the water temperature rises above 30C. Children can become infected when contaminated water is forced up the nose. The organism then reaches the base of the brain directly.
In Australia's hotter regions children should not be allowed to swim in poorly chlorinated swimming pools or stagnant waterholes, particularly on very hot days. Young children should be discouraged from playing with hoses that may force water up their noses.
Some fungi can occasionally cause meningitis, but the disease is rare and usually occurs only in patients whose immune system has been severely depressed by disease, (eg. AIDS or leukaemia, or by drug therapy). Fungal meningitis may be slow and difficult to diagnose and treat.
The symptoms of all these forms of meningitis are similar. Hospital tests may be needed to tell the difference. If in doubt seek medical advice quickly.
The Meningitis Centre is a 'not for profit' support organisation based in Australia, not a professional medical authority. Consequently the text on this web site provides general information about meningitis and septicaemia, not medical advice and is not intended for use in the diagnosis or treatment of the diseases. Please consult your doctor to discuss the information or if you are concerned someone may be ill.