Anyone can become infected with the virus. However, the very old are more likely to become ill and develop serious symptoms when infected. The chance that one mosquito bite will be from an infected mosquito is very small. If bitten by an infected mosquito, your chances of developing illness are roughly one in 300. Most mosquitoes are not infected with the West Nile virus.
Illnesses related to mosquito bites are rare.
However, you should see a doctor immediately if you develop symptoms such as high fever, confusion, muscle weakness, or severe headaches. Patients with mild symptoms are likely to recover completely, and do not require any specific medication or laboratory testing. Although there is no specific treatment, medication or cure, the symptoms and complications of the disease can be treated. Most people who get this illness recover from it. No vaccine for West Nile fever exists.