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Increase in West Nile virus Activity Prompts Advisory

Wed August 9, 2017


DuPage County-- Reports of increased mosquito batches testing positive for the presence of West Nile virus (WNV) has prompted the DuPage County Health Department to encourage county residents to protect themselves from mosquito bites and the risk of contracting WNV.

The Health Department operates a countywide WNV surveillance program, and recent positive reports from mosquitoes trapped in the county are in line with similar reports of WNV activity elsewhere in northeastern Illinois.

Residents are encouraged to check the Personal Protection Index (PPI), at The PPI is an easy-to-understand alert system that informs the public about the risk of contracting WNV, as well as the steps that should be taken to protect themselves and their families.

The current level is 2- Moderate risk, defined as: high numbers of infected mosquitoes in most areas and one confirmed human case of WNV disease in the region (Will County). The recommended actions: Drain, Defend, Dusk to Dawn.

The PPI provides residents with a current snapshot of WNV activity, ranging from zero to three, with zero being no activity and three announcing multiple human cases of WNV in DuPage County. The PPI is updated every Wednesday by Health Department staff during the surveillance season and will change to match the risk level determined for that period.

The weather forecast for the next week includes warmer temperatures, which increases the potential for the increased presence of WNV.

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

Drain: Drain those items that collect standing water around your home, yard or business. Scrub and refill pet water dishes and bird baths regularly.

Defend: Use an insect repellent containing DEET when outdoors and reapply according to directions.

Dress: Wear long pants, long sleeves and closed-toe shoes when outside to cover the skin.

Dusk to Dawn: Wear repellent outdoors during these prime times for mosquito activity.

Find more prevention tips and ways to protect yourself, protect your family on the DuPage County Health Department's "Fight the Bite" page:

Approximately one in five people who are infected with WNV will develop symptoms such as fever, headache, body aches, joint pains, vomiting, diarrhea, or rash. Less than one percent will develop a serious neurologic illness such as encephalitis or meningitis (inflammation of the brain or surrounding tissues).

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

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