There are 4 types of meningitis which are classified
by the causal agent. These 4 types of meningitis include:
Viral meningitis is more common then bacterial and generally less serious.
The most common cause of viral meningitis is coxsackievirus and echovirus
(also called enterovirus). Meningitis may also develop due to infection
of measles, polio, chickenpox viruses or because of complications due
to mumps (6).
Various types of bacterial meningitis include:
One of the most common causes of
bacterial meningitis universally is
meningococcal bacterium occurring in five
groups namely A, B, C, W135 and Y.
The bacteria live in the back of nose,
throat or upper respiratory tract. About
10-25 percent of the population is a
carrier of these bacteria without being
affected at any given point of time (7).
Septicemia: The meningococcal
bacterium is also the causal agent for
Meningococcal septicemia. The
meningococcus infects the meninges by
entering through the blood stream. The
bacterium multiplies in the blood stream
simultaneously releasing toxins, thus
poisoning the blood (septicemia). The
septicemia is a medical emergency with
fatality rates as high as 20 percent (8).
Pneumococcus or Streptococcus pneumonia causes
this types of meningitis. People of any age
group, especially babies and children under the
age of 18 months, are susceptible to infection by
this type of meningitis. Elderly people with a
defective immune system are also at risk of being
Hib Meningitis: The causal agent for
this type of meningitis is Haemophilus influenzae type B, generally
affecting infants (10).
TB Meningitis: The bacterium bacillus
tubercle causes this type of meningitis. Normally, elderly people
and those with underlying TB infection
are susceptible to this type of infection. The lungs are usually infected
first and later it travels to brain through the blood stream (11).
Neonatal Meningitis: Meningitis affecting
new-born babies is called neonatal meningitis. Premature babies are
at a greater risk and fatality rates are as high as 20%. Escherichia
coli and B streptococcal bacteria i.e., Streptococcus agalactiae cause
neonatal meningitis (12).
Fungal meningitis is rare and caused by
Cryptococcus (Cryptococcus neoformans).
Generally, immuno-compromised patients such as
those suffering from AIDS and leukemia are most
susceptible to this type of meningitis (13).
It is a very rare and very serious illness often leading to death.
The infection is caused by amoeba living in geothermal pools and stagnating
pools of fresh water at temperatures of 86-degree Fahrenheit, (30º
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