All About Meningitis

In addition to germ infections, meningitis can also be caused by non-infectious causes.
All About Meningitis

Written by Equipo Editorial

Last update: 20 May, 2023

Meningitis is the inflammation of the membranes that cover the brain, known by the name of meninges, and of the fluid that occupies the space between them, the cerebrospinal fluid. Normally, it develops from an infection. Find out all about meningitis in this article.

Any germ that infects the body can cause meningitis. The types of meningitis that are caused by viruses are benign, although the most serious are those caused by bacteria. Among all bacteria, pneumococcus, and meningococcus are responsible for more than half of acute meningitis in many countries.

Anyone can get meningitis, but the frequency of the disease is especially high in children and people with weakened immune systems. In developed countries, bacterial meningitis affects about 3 people per 100,000 inhabitants per year.

How does meningitis occur?

Viral infections are the most common cause of meningitis. Bacteria would occupy the second position and, finally, fungal infections. As we have seen, bacterial infections are life-threatening. That’s why it’s essential to identify the cause.

In addition to germ infections, meningitis can also be caused by non-infectious causes. Some triggers are chemical reactions, allergies to certain medications, some cancers, and inflammatory reactions.

We’ll now find out all about meningitis and classify it according to its causes.

Bacterial meningitis

This infection occurs when the bacteria pass into the blood and reach the brain and spinal cord. It can also occur when bacteria invade the meninges directly.

This situation can appear when the patient suffers an ear infection or a sinus infection, a skull fracture, or after a surgical intervention.

A girl with earache.

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These are the most common strains that trigger meningitis:

Streptococcus pneumoniae or pneumococcus

This is the most common cause of bacterial meningitis in babies, young children, and adults. Today there’s a vaccine that can prevent it. Meningitis caused by this bacterium occurs with:

  • Pneumonia
  • Ear infections
  • Sinus infections

Neisseria meningitidis or meningococcus

This is also one of the main causes of this disease. It usually causes an upper respiratory infection, but causes meningococcal meningitis when it enters the bloodstream.

It’s an infection with a high degree of contagion that affects, to a greater extent, adolescents and young adults. Because it’s easily spread, it’s common for it to cause local epidemics in student residences. There’s also a vaccine to prevent this infection.

Haemophilus influenzae or hemophilus

Haemophilus influenzae type b was, at one time, the leading cause of this disease in children. However, thanks to the development of new vaccines against this bacterium, the number of infections of this type has been considerably reduced.

Listeria monocytogenes or listeria

Listeria is a bacteria that can be found in unpasteurized cheeses, hot dogs, and cold cuts.

Women who are pregnant, newborn babies, older adults, and people with weakened immune systems are the most vulnerable people. This bacterium is able to cross the placental barrier, so infection in an advanced stage of pregnancy can be fatal for the baby.

Viral meningitis

Normally, this type of infection is, as we have mentioned, mild in nature and usually disappears on its own. The responsible viruses are usually known as “enteroviruses”. Infections with this virus are more frequent in late summer and early fall.

Other serotypes that can cause meningitis are:

Fungal meningitis

This is the least common type of meningitis. An infection of these characteristics produces chronic meningitis, which manifests itself within two weeks or more. The signs and symptoms are similar to those of acute meningitis, which we’ll see later.

Fungal meningitis is not contagious and life-threatening if not properly treated with antifungal drugs.


When a person is infected, they can develop the first symptoms between 2 and 10 days. Sometimes this illness begins with flu-like symptoms. The most frequent and serious are:

  • High fever
  • Severe headaches
  • Stiff neck
  • Vomiting
  • Seizures, agitation, and/or delirium
Brain memories mental disorders.

How can it be diagnosed?

For the diagnosis of meningitis, it’s necessary to study the cerebrospinal fluid. To do this, an extraction must be made by means of a lumbar puncture. In addition, it has to be done as soon as possible because, as we have seen, meningitis can be a fatal disease.

Sometimes the lumbar puncture is postponed until a CT scan or Magnetic Resonance is obtained. Analysis of cerebrospinal fluid can identify the causative agent of meningitis in most patients.

Apart from this analysis, other tests can also be done that can help the diagnosis. Among them we can mention:

  • Blood cultures
  • Otorhinopharyngeal samples.
  • Stool samples: This type of test is often required when a viral infection is suspected.


People with this viral disease tend to heal on their own. However, bacterial and fungal infections require treatment.

Regarding the bacterial one, the treatment consists of specific care in the hospital in addition to the administration of an intense treatment based on antibiotic drugs. Intravenous fluids and medications can also be given to treat associated injuries that may appear, such as brain edema, shock, or seizures.

In order to avoid complications, it’s essential to carry out an early diagnosis and prompt specialist assistance.

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