Meningitis is the inflammation of the meninges. The meninges are a layer of connective tissue that surrounds the brain. Viruses or bacteria can be possible triggers for meningitis. Often it can also happen that in the course of this meningitis an inflammation of the brain (encephalitis) occurs. In this case, one speaks of a meningoencephalitis.
The risk group for meningitis includes children, as well as people with a weakened immune system. In developing countries, meningitis is one of the most common infectious diseases.
In the western industrialized countries, however, the number of people suffering from meningitis is around 0.5 to five per 100,000 inhabitants and thus occurs only very rarely. The most common cause of meningitis in children is the so-called meningococcus, which belongs to the class of bacteria.
In general, it can be said that the number of meningitis is decreasing. The reason for this is the introduction of vaccinations against the most common meningitis pathogens, such as the Haemophilus influenzae type b vaccination, the meningococcal vaccination, the pneumococcal vaccination and the vaccination against the virus-triggered early summer meningoencephalitis (FSME).