Encephalitis, literally meaning inflammation of the brain, is a viral disease caused by many

viruses that cause the brain to swell. It can also be caused by exposure to harmful chemicals as

well as a complication of another disease. The strains of this pathogen that are present in North

America include western encephalitis, eastern encephalitis, La Crosse, and St. Louis encephalitis.

These viruses infect all ages and sexes equally, however the fatality rate is much higher in infants

and the elderly.

This deadly, but highly unknown disease is carried to it's victims through mosquitoes, and

occasionally ticks. These arthropods pick up the virus from an infected host, usually birds,

horses, or cows, and carry it for four to fourteen days, or faster when warm weather is present.

This allows the virus to replicate. At this time, they are able to infect humans and other animals

with the virus.

Once contaminated, the person may not notice symptoms for one or two weeks. At the

end of that time he will notice drowsiness, headaches, stupor, abnormal vision, and sleep

disturbances in normal cases. In more severe cases, the infected party may experience seizures,

paralysis, cardiac or respiratory arrest, and he may go into a coma. Thirty-eight percent of these

severe cases will end in death after two weeks.

When a physician suspects that a patient may have encephalitis, he will first observe the

symptoms. If these symptoms continue to point toward the virus, the doctor will perform a

lumbar puncture, checking the the pressure as the fluid drains. Then he will examine the spinal

fluid, looking for high amounts of white blood cells or proteins. Now the doctor must isolate the

virus or do a blood work-up to be sure this is the disease the patient has been infected with.

When this procedure is not correctly followed, the patient can be misdiagnosed as having multiple

sclerosis, polio, or meningitis.

Encephalitis has no cure, but most of the symptoms can be treated. In order to recover

quickly, it is recommended that the patient gets plenty of bed rest and that he stay under medical

supervision for the duration of the illness. Even when he follows these instructions, he may be

sick for several months, and there is a 25% chance that the patient will never fully recover.

There are no vaccines for encephalitis, but with proper precautions it can be prevented.

The best way to avoid the virus is to avoid mosquitoes. Some things you can do include wearing

insect repellent, wearing long sleeves and pants, and fixing window and door screens in the home.

You can also encourage your city government to invest in finding mosquito breeding sites,

population and density. When the city knows these things, they are able to control high

population with larvivorous fish or insecticides.

Bibliography

Encyclopedia

Weller, Thomas H. "Encephalitis." The World Book Encyclopedia,

1981

"Encephalitis." Microsoft Encarta Encyclopedia. 1997

Specialized Encyclopedia

Kunz, Jeffrey and Asher Finkel, editors. "Encephalitis."

The American Medical Association Family Medical Guide.

1987

Baldridge, Iona C. "Encephalitis." Health and Illness. 1995

Books

Benarde, Melvin A. Our Precarious Habitat. New York: Norton

Publishers, 1970

Textbooks

Johnson, George B, editor. Biology: Visualizing Life. Austin: Holt,

Rinehart, & Winston, 1998

Internet

"Human case of eastern equine encephalitis confirmed in southeastern

Massachusetts" http://www.magnet.state.ma.us/dph/eeepress.htm

Other resources

Guralnik, David B. Webster's New World Dictionary.

New Jersey: William Collins Publishers, 1980