West Nile Virus
West Nile virus (WNV) is a mosquito-borne virus that can cause serious, life-altering disease or death. People get WNV through the bite of an infected mosquito. In a very small number of cases, WNV also has been spread through blood transfusions, organ transplants, breastfeeding and, during pregnancy, from mother to baby. It is not spread person-to-person by casual contact.
Most people infected with WNV will have no symptoms at all. Some people will have mild symptoms such as fever, nausea and rash, and some will develop serious disease that can include high fever, convulsions, paralysis and, in some cases, lasting neurological effects. People who develop symptoms of severe WNV illness, such as unusually severe headaches or confusion, should seek medical attention immediately. Severe WNV illness usually requires hospitalization.
The best protection against WNV is to avoid mosquito bites: use insect repellent, wear long sleeves and long pants, keep window and door screens in good repair, and dump out standing water around your home where mosquitoes can lay their eggs.