Causes of meningitis
In 80% cases the main reasons, caused meningitis, are three types of bacteria: Neisseria meningitidis, Nemophilus influenzae and Streptococcus pneumoniae. Normally they exist in the environment and may even be present in the human upper respiratory tract, causing no harm.
But sometimes, these micro-organisms, without apparent reason, infect the brain. In other cases meningitis developed after head trauma or a consequence of immune system weakening.
Most often it affects people, who abuse alcohol, post-splenectomy (removal of the spleen) or pneumococcal pneumonia, as well as with chronic inflammatory diseases of the ear and nose, or sickle cell anemia.
More rarely, other types of bacteria cause meningitis too. Among them, Escherichia coif, normally present in feces, and Klebsiella. Diseases caused by these bacteria, often developing after head injuries, operations on the brain and spinal cord, or as a result of sepsis, as well as represent infections acquired in hospital.
These diseases are most prevalent in people with damaged immune systems. For those who have renal insufficiency or taking corticosteroids, increased risk of meningitis caused by other bacteria - Listeria.
Meningitis is more common in children at an early age and is rare for adults, if there are no special risk factors. However, among people living in close contact, such as in military camps and hostels, there may be outbreaks of meningococcal meningitis epidemics and other infections.
