Meningitis is the acute inflammation of the protective lining around the brain and the spinal cord. In most cases, it is caused by an infection. The protective membranes are called meninges, which get affected by meningitis.

The infection occurs mostly in children, young adults and those who have a long history of health problems. This is because the immune system is weak in such people, which makes them more susceptible to infections.

The symptoms of meningitis include prolonged fever, headache, vomiting, seizures, rashes, cough, breathing problems, flu, stiff and painful neck, disorientation, increased sensitivity to loud noise, and harsh light. Irritability and drowsiness can also become signs of meningitis when combined with the other symptoms.

Causes of meningitis

Meningitis is a severe disorder because it can become fatal due to the inflammation’s proximity to the brain and the spinal cord. It is categorized as a medical emergency. The inflammation can be caused by viruses, bacteria or some other microorganisms. The types of meningitis can be determined with the identification of the type of virus or bacteria which causes it. There are some types of meningitis which can be prevented with the help of immunization. Meningitis can have long-term effects such as epilepsy, deafness, hydrocephalus and cognitive disorders.

The inflammation that occurs in the membrane is not directly caused by the bacterial infection. It is caused because of the immune cells in the brain, which release a large number of cytokines or hormone-like mediators to send signals to the other immune cells of the body in response to the entry of foreign bodies. Innumerable white blood cells enter the cerebrospinal fluid between the membrane layers leading to inflammation and swelling.

Types of meningitis

The types of meningitis depend on its causes. Some of the types are explained here.

• Viral meningitis
  Viral meningitis is the most common type of meningitis. It is not life threatening but has some long-term effects on the person suffering from it. Enterovirus is the common cause of viral meningitis. This type of meningitis is not contagious. People can make a full recovery from it, but the recovery process is slow. There is no specific treatment for this type of meningitis because even antibiotics do not work in such cases. The only thing that the person can do is to remain hydrated by constantly consuming fluids and take painkillers. One of the after-effects of viral meningitis is memory loss.
• Bacterial meningitis
  This is a more serious type of meningitis, which needs immediate medical attention and treatment as it can be life threatening. Bacteria such as meningococcal, TB, streptococcal and pneumococcal can cause this type of meningitis. It requires an urgent intake of antibiotics so that the bacteria can be killed fast and does not pose a threat to life.
• TB meningitis
  This type of meningitis is caused by bacteria called Mycobacterium Tuberculosis. It starts with a lung infection and spreads to the membrane through the bloodstream. The bacteria multiply in the lungs and pass on to the other parts of the body. When such bacteria reach the meninges, they can cause small abscesses, which burst and lead to TB meningitis. This is also treated with the help of antibiotics.
• Meningococcal meningitis
  This meningitis is dangerous because it combines two major diseases of meningitis and septicemia or blood poisoning. This is caused by a bacteria called meningococcus. This type of meningitis is contagious through a cough and sneezing. The bacteria enter the bloodstream by penetrating the lining at the back of the throat. They poison the blood as they get mixed with the bloodstream and can affect the meninges. Pneumococcal meningitis is also caused similarly by bacteria called pneumococcus and has the same effect on the body.
• Neonatal meningitis
  This type of meningitis occurs in newborn babies within the first 28 days of their lives. Babies have a fragile immune system, and hence, are very vulnerable to infection. Infection can cause neonatal meningitis from streptococcal, E.coli and Listeria bacteria.

These are just a few major and common types of meningitis. There are many more types, which are not discussed here. But all of them are caused by infection and can be highly detrimental to the health of the person affected.

The treatment of meningitis is most commonly done with a range of antibiotics. Intravenous fluids need to be administered if the vital stats of a person are affected such as low blood pressure. Ventilation may be required if the person has severe respiratory problems. Cerebral perfusion pressure is applied to reduce intracranial pressure between the membranes with the help of medication. The empiric antibiotics need to be immediately started, and corticosteroids can help to reduce the long-term effects of this disease.