What Is Encephalitis?
Encephalitis is inflammation of the brain tissue. Most cases are caused by viral infections. In rare cases it can also be caused by bacteria.
There are two main types of encephalitis—primary and secondary. Primary encephalitis is when a virus directly infects the brain and spinal cord. Secondary encephalitis is when an infection that starts elsewhere travels to your brain.
This disease is rare. According to the Centers for Disease Control, encephalitis occurs in one of every 2,000,000 people (CDC). Most people who contract it are young children, individuals over 65, or those with weak immune system.
Though rare, the disease is very serious—severe cases can cause death. If you have symptoms of encephalitis, seek medical attention.
(http://www.healthline.com/health/encephalitis#Overview1)
