West Nile Virus

West Nile virus is an arthropod-borne virus (arbovirus) most commonly spread by infected mosquitoes. West Nile virus can cause febrile illness, encephalitis (inflammation of the brain) or meningitis (inflammation of the lining of the brain and spinal cord).

Most people get infected with West Nile virus by the bite of an infected mosquito. Mosquitoes become infected when they feed on infected birds. Infected mosquitoes can then spread the virus to humans and other animals. In a very small number of cases, West Nile virus has been spread through blood transfusions, organ transplants, and from mother to baby during pregnancy, delivery, or breastfeeding.

Most people (70-80%) who become infected with West Nile virus do not develop any symptoms.

About 1 in 5 people who are infected will develop a fever with other symptoms such as headache, body aches, joint pains, vomiting, diarrhea, or rash. Most people with this type of West Nile virus disease recover completely, but fatigue and weakness can last for weeks or months.

Less than 1% of people who are infected will develop a serious neurologic illness such as encephalitis or meningitis (inflammation of the brain or surrounding tissues). The symptoms of neurologic illness can include headache, high fever, neck stiffness, disorientation, coma, tremors, seizures, or paralysis.


  • Avoid mosquito bites.
    • Use insect repellents when you go outdoors. The CDC recommends repellents containing DEET, picaridin, IR3535, and some oil of lemon eucalyptus and para-menthane-diol products provide longer-lasting protection. To optimize safety and effectiveness, repellents should be used according to the label instructions.
    • Avoid being outdoors during peek mosquito biting hours from dusk to dawn. If outdoors, wear protective clothing and repellent during this time. Spraying your clothes with insect repellent is also recommended as mosquitoes may bite through thing clothing.
  • Tip ‘n Toss.
    • Reduce the mosquito population around your business, home or property by eliminating all standing water and debris.
    • Trim or remove overgrown plants that provide cool/dark/damp areas where adult mosquitoes rest.
    • Repair missing, damaged, or improperly installed screens.
    • Fix leaky faucets that create pools of water.


For more information visit www.cdc.gov/westnile or dph.georgia.gov/mosquito-borne-viral-diseases.