Encephalitis
Primary, Post-infectious & Unspecified

What is encephalitis?

Encephalitis is a medical term that refers to an inflammation of the brain.

Two closely related terms are:

1. Encephalomyelitis, which refers to an inflammation of the brain and spinal cord.
2. Meningoencephalitis, which refers to an inflammation of the brain and the meninges (the membranes that cover the brain and spinal cord).

Encephalitis can be caused by a number of viruses, bacteria and poisons (such as lead).

Primary encephalitis:
Describes the situation where the cause of the encephalitis is known and is believed to be responsible for the patient’s symptoms.

Post-infectious encephalitis:
Also known as acute disseminated encephalomyelitis. This describes a situation where the patient has recovered recently from an illness, and develops encephalitis at a subsequent date.

Unspecified encephalitis:
Describes the situation where the cause of the encephalitis is unknown.

What are the symptoms of encephalitis?

The symptoms of encephalitis vary depending on the cause of the encephalitis. The central nervous system effects can be very mild and produce symptoms no worse than a headache, or they can be very severe and result in coma or death. Depending on the cause of the encephalitis, other body systems may also be affected.

Why is encephalitis considered a reportable disease?

Encephalitis is a rare but very serious disease. Many of the causes of encephalitis are communicable and, if one case of encephalitis is diagnosed within a community, appropriate steps may need to be taken immediately to prevent the further spread of the disease.

Where can I get more information?

Contact your physician or the Southern Nevada Health District, Office of Epidemiology at (702) 759-1300.