Meningitis means inflammation of the meninges — the lining around the brain and spinal cord. It is usually caused by a bacterial or viral infection. Viral meningitis is usually mild, however, bacterial meningitis is a medical emergency and can result in death or permanent disability if treatment is not undertaken.
Most cases of meningitis in Australia are caused by one of 3 different types of bacteria: the meningococcus bacterium (scientific name Neisseria meningitidis), the pneumococcus bacterium (scientific name Streptococcus pneumoniae) and Haemophilus influenzae.
These bacteria can also cause septicaemia, where the bacteria invade the bloodstream. This is also a medical emergency and can result in death.
Since immunisation against Haemophilus influenzae type B became part of the national vaccination programme in 1992, meningococcus and pneumococcus have been the most common causes of bacterial meningitis.
The National Immunisation Program Schedule now also includes immunisation against several strains of pneumococcus and the group C strain of meningococcus, leading to a significant reduction in cases of pneumococcal and meningococcal meningitis as well.
All 3 of these bacteria can live in the nose and throat of some adults and children without affecting them or causing them to be unwell, however, these people can infect others by coughing or sneezing on them. About one in 10 Australians carries the meningococcus bacterium in their respiratory tracts, without suffering any disease themselves. This carriage rate may be higher in groups of people living in crowded conditions. People who smoke are more likely to be carriers than non-smokers.
When a carrier of meningococcus coughs or sneezes, tiny droplets are sprayed into the air and can be breathed in by other people. A small proportion of these people may go on to develop meningitis. Kissing is another way that the bacteria can be spread from one person to another.
The symptoms of meningitis in babies and young children include:
Symptoms in older children may also include:
Meningitis can lead to death within hours so urgent medical attention must be sought if you suspect a baby or child has meningitis. A doctor must give antibiotics as soon as possible for the best chance of recovery. An early injection of steroids is also recommended.
As mentioned earlier, the Haemophilus influenzae type B (Hib) vaccination programme has drastically reduced the incidence of meningitis due to Hib in Australia.
In Australia there are 2 types of vaccine available against meningococcus. One is effective against meningococcal disease caused by a type of meningococcus called group C, which is common is Australia. This vaccine is now routinely given in childhood. The other vaccine is effective against 4 other serotypes of meningococcus. This vaccine is not recommended for routine vaccination in Australia, but is used as a travel vaccine for people going to parts of the world where these 4 serogroups of meningococcus are common — particularly pilgrims to attending the annual Hajj in Saudi Arabia.
One of the problems of developing a vaccine against a disease-causing bacterium, such as Streptococcus pneumoniae, is that even within a particular species there may be different subtypes which exist. Unfortunately, a vaccine offering protection against one type won’t offer protection against another type. In the case of Streptococcus pneumoniae, at least 90 different types have been identified.
Two vaccines are available in Australia: one offers protection against the 23 most common or most disease-causing types of pneumococcus (the 23-valent pneumococcal polysaccharide vaccine — 23vPPV); the other offers protection against the 7 serotypes that cause the majority of invasive pneumococcal disease in young children in Australia (the 7-valent pneumococcal conjugate vaccine — 7vPCV).
The pneumococcal conjugate vaccine (7vPCV) is now recommended for all children, and is given as part of the National Immunisation Program Schedule. Recommendations for vaccination with 23vPPV depend upon your age and whether you belong to a group particularly at risk of pneumococcal disease, such as Aboriginal or Torres Strait Islander people.
| Meningitis: what the words mean | |
|---|---|
| Bacterium | Singular of bacteria, a type of germ. |
| Meningitis | Inflammation of the membrane covering the brain and spinal cord. |
| Meninges | Membrane covering brain and spinal cord. |
| Meningococcal infection | This can result in meningitis or septicaemia or both. |
| Meningococcus | Common name for a type of bacterium called Neisseria meningitidis. |
| Pneumococcus | Common name for a bacterium called Streptococcus pneumoniae. |
| Septicaemia | Blood poisoning. Invasion of the bloodstream by disease-causing bacteria, viruses or fungi. |
| Serotype | A subdivision of a particular species of bacterium or virus based on characteristic proteins it possesses. |
Last Reviewed: 19 October 2009