West Nile Virus in Children

What is West Nile virus?

West Nile virus (WNV) is a seasonal epidemic in North America that occurs during the summer and fall — the mosquito months. WNV is most often spread by mosquito bites. Most children infected do not have any symptoms. Currently, there is no preventive vaccine or medication to treat the virus.

The overall risk of becoming infected with West Nile virus can depend on:

  • Time spent outdoors: People who spend a lot of time working or playing outdoors are more at risk of getting West Nile virus because they have a greater chance of being bitten by an infected mosquito. 
  • Time of year and day: In North America, cases of West Nile virus are more frequent between from July through early September, when the mosquito population is at its peak. Mosquitoes are also most active during dusk and dawn, especially in damp or heavily wooded areas.
  • Geographic region: Cases of West Nile virus have been reported in most parts of the United States, but the highest rates are seen in Western and Midwestern states.