Meningitis (general)

Meningitis is the inflammation of the meninges. The meninges are a layer of connective tissue that surrounds the brain. Viruses or bacteria can be possible triggers for meningitis. Often it can also happen that in the course of this meningitis an inflammation of the brain (encephalitis) occurs. In this case, one speaks of a meningoencephalitis.

The risk group for meningitis includes children, as well as people with a weakened immune system. In developing countries, meningitis is one of the most common infectious diseases.

In the western industrialized countries, however, the number of people suffering from meningitis is around 0.5 to five per 100,000 inhabitants and thus occurs only very rarely. The most common cause of meningitis in children is the so-called meningococcus, which belongs to the class of bacteria.

In general, it can be said that the number of meningitis is decreasing. The reason for this is the introduction of vaccinations against the most common meningitis pathogens, such as the Haemophilus influenzae type b vaccination, the meningococcal vaccination, the pneumococcal vaccination and the vaccination against the virus-triggered early summer meningoencephalitis (FSME).

The main causes of meningitis are bacteria and viruses. In rare cases, fungal or parasitic meningitis can also occur and, even more rarely, a malignant cancer can be the cause of a so-called meningeosis carcinomatosa. Radiation can also cause irritation of the meninges.

Mostly people with a weak immune system are affected by meningitis. The pathogens are localized in the bloodstream and thus enter the brain, or they migrate from surrounding organs. As an example of this, a middle ear infection (otitis media) or a sinus infection (sinusitis), for example, can trigger meningitis in rare cases.

Bacterial meningitis:

The most common cause of meningitis is considered to be a group of bacteria called meningococci. Pneumococcus comes second, as well as other bacteria, such as Haemophilus influenzae. The reason why meningitis suddenly occurs in healthy people has not yet been clarified. Meningococci are sometimes also found in the nasopharynx in healthy people. There they normally behave inconspicuously, but can be transmitted to other people.

Viral meningitis:

Viral meningitis often occurs at the same time as another viral disease. For example, some mumps patients have been diagnosed with viral meningitis. The meninges can also be a target for the chickenpox and measles virus. Ticks can also transmit a type of meningitis known by the short form TBE.

The most obvious symptom of meningitis is stiff neck (meningismus). Thus, there is an increase in pain when you bend your head forward. If hearing disorders also occur, this is a sign of a bacterial concomitant inflammation of the inner ear (labyrinthitis).

Further signs are:

• Strong feeling of illness
• Headache
• High fever
• Vomiting
• Increased sensation of pain
• Light shyness
• Confusion and dizziness, which can even lead to coma

In children, these symptoms of the disease are less pronounced and evident. The younger the affected person, the more difficult it is to make a diagnosis. These patients often experience severe abdominal pain and, in some cases, epileptic convulsions.

Another symptom of meningococcal meningitis may be small dot-like hemorrhages on the skin called petechiae. This is considered a sign that the bacteria are in the bloodstream. This condition is considered to be extremely urgent. In this case, a doctor should be consulted immediately, who will initiate appropriate antibiotic therapy.

The first examination for suspected meningitis is a lumbar puncture, in which cerebrospinal fluid (CSF) is taken from the spinal canal and examined for signs of infection and pathogens (CSF diagnostics).

A characteristic symptom of meningitis caused by bacteria is a purulent, cloudy cerebrospinal fluid. In the case of viral or parasitic inflammation, on the other hand, the cerebrospinal fluid is visually unchanged, which is why the diagnosis is more complex. In addition, a blood sample is taken and examined for bacteria and general signs of inflammation, such as an increase in inflammatory cells (leukocytes).

A particularly rapid result is obtained using polymerase chain reaction (PCR). In this method, the genetic material (DNA) of the pathogen is multiplied, from which it can be concluded that the pathogen is present at all. The short waiting time for the result is particularly useful in cases of suspected meningitis, as this disease requires immediate treatment. However, PCR can only be used for certain pathogens.

The advantage of computer tomography (CT) or magnetic resonance imaging (MRI) is that it is possible both to determine where the pathogen is coming from (for example, suppurated sinuses) and to indicate complications such as accumulations of pus (empyema) or fluid in the brain (hydrocephalus).

If meningitis is suspected, a doctor should be consulted immediately. If the diagnosis of meningitis is considered certain, further treatment takes place in hospital in a neurological department.

Bacterial meningitis:

Bacterial meningitis is treated with antibiotics. The drugs are injected directly into the veins or administered as an infusion (venous drip). The choice of antibiotic depends on the particular bacterium.

In most cases, a combination of different antibiotics is given at the beginning, for example cephalosporin and amoxicillin. The reason for using several antibiotics at the same time is the lack of time, because the detection of the pathogen often takes longer, but in the case of meningitis one has to act quickly. Once it is clear which pathogen has caused the meningitis, only the substance that is most effective against the type of bacteria is given. Sometimes the doctor supplements the treatment with cortisone.

To prevent further infection, an antibiotic is given to all those who have had contact with the sick person to stop further spread of the pathogen.

Viral Meningitis:

Since there is no medication to treat viral meningitis, only the symptoms are treated. An exception are the inflammations that are triggered by viruses from the group of herpes viruses. These include herpes simplex, varicella-zoster, cytomegalovirus and the Epstein-Barr virus. Antiviral drugs (virustatics) can be used to prevent viruses from continuing to multiply unhindered in the body.

Patients affected by viral meningitis should in any case remain under observation as inpatients. The focus is on reducing possible fever, relieving headaches or, in rare cases, stopping an epileptic seizure.

Bacterial meningitis:

If bacterial meningitis is not treated, it can take a lethal course. Since the disease progresses very quickly in some cases, some patients die despite the best possible treatment. The probability of succumbing to meningococcal meningitis is about ten percent. In the case of a pneumococcal infection, up to 25 percent die, and if listeria is the trigger for the disease, only up to 50 percent of those affected survive.

Even after surviving meningitis, secondary diseases of the nervous system can still occur, such as impaired vision or hearing, epilepsy, coordination disorders and paralysis.

Viral meningitis:

Viral meningitis usually has a less life-threatening course than bacterial meningitis. Fewer patients also develop secondary illnesses. It is important to survive the first critical day of the disease without complications, after which the chances of recovery are largely good.

Vaccinations are available against some of the pathogens that cause meningitis. These include:

• Haemophilus influenzae type b (Hib).
• Meningococcus
• Pneumococcus

Since 2006 there is a vaccination recommendation from the Permanent Vaccination Commission (STIKO) at the Robert Koch Institute for children as basic immunization. The TBE vaccination is also recommended for people who live in the area where TBE is spread. Ticks are considered to be carriers of TBE, which is why appropriate tick protection is advisable.

If a child or adult suffers from fever, stiff neck, nausea and severe feeling of illness, a doctor should be informed immediately.

Persons who have been in contact with the affected person should also seek medical attention. The type of preventive antibiotic therapy depends on the type of causative pathogen. Any suspicion of meningococcal meningitis must be reported to the health authorities, as appropriate action must be taken. Patients suffering from meningococcal meningitis are isolated in hospital for at least 24 hours after the start of antibiotic therapy.