West Nile Virus Information

West Nile Virus is transmitted by mosquito bites.

Incubation period in humans (i.e., time from infection/bite to onset of
disease symptoms) for West Nile disease is usually 2 to 15 days.

Most people (about 4 out of 5) who are infected with West Nile virus
will not develop any type of illness.

About 20% of people who become infected with WNV will develop West Nile
fever.

Symptoms include fever, headache, tiredness, and body aches,
occasionally with a skin rash (on the trunk of the body) and swollen
lymph glands.

It is estimated that approximately 1 in 150 persons infected with the
West Nile virus will develop a more severe form of disease.

People may develop a brief, WNF-like illness (early symptoms) before
they develop more severe disease.

The symptoms of severe disease (also called neuroinvasive disease, such
as West Nile encephalitis or meningitis or West Nile poliomyelitis)
include high fever, headache, neck stiffness, stupor, disorientation,
coma, tremors, convulsions, muscle weakness, and paralysis.