Always bear in mind that meningitis can be caused by a virus or bacteria. It is vital to be familiar with the differences between the 2 types of meningitis so that proper action can be taken.
With the help of vaccination programs, the types of bacteria that can cause meningitis have drastically reduced. Nevertheless, there are still strains of bacteria that could not be effectively managed by vaccines.
Neisseria meningitidis bacteria
The Neisseria meningitidis bacteria or meningococcal bacteria are known to cause the bacterial type of meningitis.
Streptococcus pneumoniae bacteria
The bacteria are often referred to as pneumococcal bacteria. This tends to affect infants and young children since their immune systems that have not established immunity to the bacteria.
How the bacteria spread?
The meningococcal bacteria responsible for causing the condition could not survive for long periods outside the body, thus they typically spread via extended close contact. The bacteria can spread via coughing, sneezing, kissing, sharing of utensils and personal possessions.
Since most individuals especially adults over 25 years old have natural immunity to the meningococcal bacteria, most cases of bacterial meningitis are isolated incidents. Nevertheless, there is a risk for a small outbreak of cases in areas where many individuals live in close proximity.
The pneumococcal bacteria readily spread than the meningococcal bacteria and passed on via sneezing or coughing. Nevertheless, in most circumstances, they only trigger mild infections such as middle ear infection.
Just like with bacterial meningitis, vaccinations have successfully eliminate the threat from various viruses that can cause viral meningitis.
The MMR vaccine (measles, mumps and rubella) provides children with immunity against mumps which was once a main cause of viral meningitis in children. Nevertheless, there are still other viruses that can cause the condition such as enteroviruses and the herpes simplex virus.
During a meningitis infection
In most cases of meningitis, viruses or bacteria spread via the blood. This infection can start in one part of the body such as the lungs or throat before moving via the tissue and into the bloodstream.
It is important to note that the brain is protected from infection by the blood-brain barrier which is a dense membrane that filters out impurities from the blood before allowing entry into the brain. Nevertheless, in some individuals, the infection can pass through the blood-brain barrier and infect the meninges.
The immune system reacts to the infection by causing the meninges to swell in an attempt to thwart the spread of infection. The swollen meninges can impair the brain and the nervous system.
The viruses or bacteria can also infect the cerebrospinal fluid (CSF) that surrounds and supports the brain and spinal cord. In case the cerebrospinal fluid is also infected, it can cause the meninges to end up more swollen, thus resulting to elevated pressure in the skull that presses on the brain which is called as intracranial pressure.