What is meningitis? It is the inflammation of the membranes that coat the central nervous system, known as meninges. Since it causes abnormal inflammation in our body, this inflammation is known as a pathology or disease. The good news is that this disease is currently not very common.
It is normally caused by infectious agents, the more habitual being viral meningitis while the bacterial case is more serious.
Meningitis can end up damaging the brain. It can even lead to death, that is why it is essential that you diagnose it and start to treat it as early as possible.
What are the meninges?
Imagine for a minute that our brain is a type of fruit. This fruit contains a nut and a liquid inside of it. The liquid travels through various points of the nut in order to keep it in good condition.
Now, imagine that the skin of the fruit is the skull and that what is under the skin, the nut, is our brain- soft, smooth, and fragile. Underneath the skin- the external layer-of the fruit, there are three other layers-inside-through which the liquid circulates to preserve the fruit.
These three layers below the skull are the meninges, three membranes that coat and protect the brain and the spinal cord, also known as the central nervous system.
Remember that the brain and the spinal cord are the most protected organs in the body. The meninges not only absorb blows, but also act as “filters” to keep dangerous microorganisms from entering the central nervous system. A cerebrospinal liquid circulates through the meninges, it also has protectant and immune functions.
Distribution of meningitis
Meningitis has become known as a frequent epidemic on the continent of Africa, especially in subsaharan Africa during the dry season. The epidemics in this zone last between two and three years and are interrupted by periods of rain. The lack of medical attention causes high mortality rates in the population.
The gravest meningitis epidemic that took place in this area was in the year 1996, causing more than twenty-five thousand deaths. In western countries, bacterial meningitis affects three in every one-hundred thousand people, and the viral affects ten in every one-hundred thousand.
- Dry seasons
- Contagious infections
Causes of meningitis
Meningitis is normally caused as a consequence of another infections– usually a virus- but there are also non-infectious cases of meningitis.
- Simple herpes virus
- West nile virus. Transmitted through mosquitos.
According to the age of the individual, there are different risks of infection caused by different microorganisms.
- Newborns under three months.
- Group B Streptococcus
- E Coli
- Children over three months
- Neisseria meningitidis
- Streptococcus pneumoniae
- Haemophilus influenzae
- Neisseria meingiditis
- Streptococcus pneumoniae
- Listeria monocytogenes
How does the disease show up?
The microorganisms get into the meninges through the blood stream, either directly or by contiguity.
The bacteria that are normally found in the nose, mouth and pharynx without causing harm pass through the blood stream. From there, they cross the blood-brain barrier in the zones where it is most vulnerable. The bacteria reaches the cerebrospinal fluid of the subarachnoid space and causes infection in the meninges.
The other ways of transmission are direct, this is causes by fractures in the skull, surgical interventions, etc. or the transmission by contiguity from the zones like the paranasal sinuses.
- Fever, especially in kids and newborns.
- Shaking and chills
- Nausea and vomiting
- Stiff neck
- Decreased levels of consciousness
The diseases comes about abruptly, with fever, headaches, nausea and vomiting; however, in children it can be less specific symptoms like irritability and drowsiness.
Cerebral edema is an injury associated with inflammation. This provokes an increase in the intracranial pressure which makes it hard for blood to reach the brain. The brain does not get enough oxygen and the brain cells start to die. In some cases, especially if the meningitis is not treated, the brain injury can be deadly.
Although the suspicion of meningitis is always clinical, getting an exact diagnosis is done through lumbar puncture.
Remember that lumbar puncture is a procedure that consists of the extraction of the cerebrospinal liquid through a needle that is inserted into the vertebrae.
Types of meningitis
Meningitis can be classified as viral or bacterial according to its etiological agent. Viral meningitis has a mild prognostic and does not require treatment.
Bacterial meningitis is very serious and requires hospitalization for treatment. This case has a high risk of death, even with treatment.
Also, you can divide the disease up according to its evolutionary course- acute, subacute and chronic- although this criteria is not commonly used.
The patient should be given antivirals and antibiotics as soon as possible.
To reduce inflammation and cerebral edema, corticosteroids like dexamethasone are administered. This reduces the risk of cerebral injury.
There are also general methods to help any acute infections, like drinking a lot of liquids, controlling your fever, etc.
Treatment enacted at the right time greatly reduces the presence of other problems in the long run, as well as the risk of death.
- Cognitive deficit
Newborns and adults have between a twenty and thirty percent chance of the illness being deadly. The risk decreases to two percent in older children.
Currently, a vaccine is being worked on for preventing meningitis in children. The vaccine is optional and can be administered after the child’s first two months of life.
Chemoprophylaxis programs with rifampin are carried out for those at risk of infection.