"Encephalitis" is an inflammation of the brain and can
be caused by viruses and bacteria including viruses transmitted
by mosquitoes. West Nile encephalitis is an infection of the brain
caused by West Nile virus. It is closely related to St. Louis
encephalitis virus found in the United States.
What Is the incubation period in humans
(or time from infection to onset of disease symptoms) for West
Nile encephalitis?
Usually 5 to 15 days.
What are the symptoms of West Nile encephalitis?
Mild infections have symptoms that include fever, headache, and
body aches, often with skin rash and swollen lymph glands. More
severe infection may be marked by headache, high fever, neck stiffness,
stupor, disorientation, coma, tremors, convulsions, muscle weakness,
paralysis, and rarely death. If you believe you have West Nile,
seek medical care as soon as possible.
How do people get West Nile encephalitis?
The bite of a mosquito that is infected with West Nile virus is
all it takes to transmit the infection. Mosquitoes become infected
when they feed on infected birds. After an incubation period of
1 to 2 weeks, infected female mosquitoes can then transmit West
Nile virus to humans and animals while biting. The mosquitoes
and the bites they cause do not differ from those bites of an
uninfected mosquito.
How is West Nile encephalitis treated?
There is NO specific therapy or vaccine for West Nile infection.
In more severe cases, intensive supportive therapy is indicated
which includes hospitalization.
Who is at risk for getting
West Nile encephalitis?
All residents of areas where virus activity had been identified
are at risk of getting West Nile encephalitis; persons greater
than 50 years of age have the highest risk of severe disease.
