Only 20% of infected people will show any symptoms, which usually appear 3-14 days after an infected mosquito bite.
Most symptoms will be mild, including:
About 1 in 150 infected people will have a severe infection, including:
These symptoms may last several weeks. Some effects may be permanent.
The virus is spread to humans by the bite of an infected mosquito. A mosquito can become infected by biting an infected bird.
The virus is not transmitted through casual contact from others. (such as kissing or touching)
A very small number of the cases have been infected by: blood transfusion, breast milk, organ transplant from an infected donor and during pregnancy from mother to baby.
The virus can be confirmed in Humans by testing the blood or fluid that surrounds the brain and spinal cord.
There is no specific treatment, medication or vaccine for West Nile Virus. In the most severe cases, hospitalization is required for management of symptoms and intensive, supportive care.