County issues notice of mosquitoes testing positive for West Nile virus

Reports of increased mosquito pools testing positive for the presence of West Nile virus this month has prompted the DuPage County Health Department to encourage residents to protect themselves from mosquito bites and the risk of contracting the virus.

The health department operates a countywide West Nile virus surveillance program, and recent positive reports from mosquitoes trapped in the county are in line with similar reports of virus activity elsewhere in northeastern Illinois.

Residents are encouraged to check the Personal Protection Index at The PPI provides residents with a current snapshot of West Nile Virus activity, with risk levels ranging from zero to three, with zero being no activity and three announcing multiple human cases of the virus in DuPage County. The current risk level is one, with “Localized abundance of active mosquitoes, climate conditions favorable for development of virus.” The PPI is updated every Wednesday 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 west Nile virus.

The best way to prevent the virus 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 and dawn: Wear repellent outdoors during these prime times for mosquito activity.

Find more prevention tips on the DuPage County Health Department’s “Fight the Bite” page at

Approximately one in five people who are infected with west Nile virus will develop symptoms such as fever, headache, body aches, joint pains, vomiting, diarrhea or rash. Less than 1 percent will develop a serious neurological illness such as encephalitis or meningitis (inflammation of the brain or surrounding tissues).

West Nile virus activity generally decreases in the fall when cooler temperatures arrive and especially after the first frost of the season. More information on the virus activity in Illinois is available at