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Second 2018 Case of West Nile virus in DuPage County

Wed August 15, 2018


DUPAGE COUNTY- The DuPage County Health Department is reporting the second human case of West Nile virus (WNV) in DuPage County for 2018. An Aurora resident in her 30s became ill in late July.

A recent spike in mosquito samples testing positive for WNV caused the DuPage County Health Department to remind residents of the importance of protecting from mosquito bites and the risk of contracting the virus. 

The best way to prevent WNV is to avoid mosquito bites and follow the four Ds of defense:

  • DrainDrain those items that collect standing water around your home, yard or business. Scrub and refill pet water dishes and bird baths regularly.
  • DefendUse an insect repellent containing DEET when outdoors and reapply according to directions.
  • DressWear long pants, long sleeves and closed-toe shoes when outside to cover the skin.
  • Dusk to DawnWear repellent outdoors during these prime times for mosquito activity.

Residents should check the Personal Protection Index (PPI) on the DuPage County Health Department's website for the current WNV activity. The PPI ranges in risk level from zero-to-three, with zero being no activity and three announcing multiple human cases of WNV in DuPage County.

The current level is 3: High Risk, defined as high numbers of infected mosquitoes in most areas, multiple human cases. The recommended actions: Drain, Defend, Dusk to Dawn, Dress for the outdoors with long sleeves and pants.

The PPI is updated every Wednesday at 3:00 p.m. by Health Department staff during the surveillance season and will change to match the risk level determined for that period.

The key factors in determining the degree of WNV activity are temperatures and rainfall. In hot, dry weather, mosquitoes that carry the virus (primarily Culex mosquitoes) breed in stagnant water, like street catch basins and ditches, and multiply rapidly.

WNV activity generally decreases in the fall when cooler temperatures arrive and especially after the first frost of the season.


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