Causes of Encephalitis

Encephalitis is not an everyday ailment. It is a very rare condition and may often also be referred to as brain fever. The risk is highest in babies and as your age increases, the risk of developing encephalitis decreases steadily. The elderly, because of their low immunity, may also be at a higher risk of developing encephalitis.

Though there are several causes of encephalitis, it is usually caused by viral infections. There are a lot of different types of viruses which may cause encephalitis. Though it is not infectious, breathing in the phlegm or saliva of an infected person may expose the person to the virus. Some of the other methods of exposure include:

  • Consuming contaminated foods and drinks.
  • Transfer of virus through mosquito and other insect bites.
Some of the ailments which could lead to encephalitis include polio, mumps, rabies, chickenpox, rubella and measles. The viruses associated with encephalitis include cytomegalovirus, adenovirus, Eastern equine encephalitis virus, echovirus and West Nile virus.

All of these viruses affect various parts of the body and may reach the brain to cause inflammation of the brain tissue. This is known as cerebral edema. The brain tissues begin swelling and may cause bleeding inside the skull. This may also cause destruction of the nerve cells and may eventually cause severe brain damage.

Apart from the viruses, there may be some other causes of encephalitis as well. This could occur as an allergic reaction to certain vaccinations. Some autoimmune diseases may cause destruction of the brain and nerve cells, causing inflammation in the brain. Bacteria, which cause lyme disease, tuberculosis and syphilis, may also reach the brain and cause encephalitis. There are some parasites such as toxoplasmosis and roundworms which may reach the brain and cause encephalitis. Parasites may be the cause of this condition only in those who have very low immunity. AIDS patients who have impaired immune systems are most susceptible to encephalitis due to parasites.

Apart from AIDS, one of the other risk factors for encephalitis is long term illness such as cancer.