News Release
News Release Facts

Department:

City Services

July 30, 2012

City Spraying Insecticide Tuesday and Wednesday Night

Hot, Dry Summer Weather Leads to Increase in Mosquitoes Carrying West Nile Virus; Chicagoans Should Take Commonsense Precautions to Avoid Bites

FOR IMMEDIATE RELEASE

CONTACT:  Efrat Stein, 312-747-9805

efrat.stein@cityofchicago.org

 

Today, the City of Chicago Department of Public Health (CDPH) is continuing their efforts against West Nile Virus by spraying to kill adult mosquitoes in several locations throughout the City. CDPH is also recommending that Chicagoans take common sense precautions to avoid mosquito bites.

“A hot, dry summer increases the risk of West Nile Virus infection, and the level of virus we're finding is considerably higher than what we have seen in past years at this point in the season. While we take steps to tackle the number of mosquitos, it is incredibly important that people across the City take common sense personal precautions as well to avoid West Nile Virus infection,” said Dr. Bechara Choucair, Commissioner of the Chicago Department of Public Health.

Spraying will occur in the following wards where CDPH traps recently yielded mosquitoes carrying West Nile Virus:

Tuesday July 31, 2012
Ward 7 and 10
Ward  13 and 18

Wednesday, August 1, 2012
Ward 41 and 36
Ward 40, a small sections of  wards 47, 48, and 50
Ward 29 and sections of wards 36, 30 and 37

Weather permitting, the spraying will begin at about 8:00 p.m. on both nights and continue through the night until approximately 1:00am, with licensed mosquito abatement technicians in trucks dispensing an ultra-low-volume spray.

The mild spring, followed by a hot and dry summer, has allowed for an increased abundance of West Nile virus-carrying mosquitoes throughout the City this summer. Currently, the risk of WNV transmission is high and can be expected to increase during the month of August. Out of 1,255 mosquito pools tested this year, 18.7%  have tested positive for WNV, compared to 1% that were positive at this time last year. 

In response the CDPH will increase its level of larval and adult mosquito control. The most important steps for combating WNV are the common sense personal precautions that every resident can take.

CDPH is highly recommending residents take the following steps to avoid West Nile Virus:

  • Use insect repellant containing DEET,Picaridin, or Oil of Lemon Eucalyptus.
  • Consider limiting outdoor activity after dark (dusk to dawn), which is when Northern House Mosquito is most active.
  • When outside between dusk and dawn, wear loose-fitting, light-colored clothing that includes long pants, long-sleeved shirts, socks and shoes.
  • Check to see that all screen on doors and windows are tight-fitting and free of holes and tears.
  • Encourage neighbors to exercise precautions.

To limit mosquito breeding opportunities, CDPH officials recommend:

  • draining and replacing water in birdbaths and children's backyard wading pools every four to five days;
  • properly disposing of old tires, jars, cans, pans, bottles, buckets and other unwanted containers that can hold standing water;
  • making sure that rain gutters, downspouts, swimming pools and pool covers are free of standing water;
  • keeping grass and weeds cut short to eliminate hiding places for adult mosquitoes

In 2011, some 712 human cases (43 of them fatal) of West Nile-related illness were reported nationally. In Illinois, there were 34 reported cases (8 of them in Chicago) and no deaths.

Thus far in 2012 2 human cases have been reported in Illinois and are in Cook County.

Human infections occur when people are bitten by a mosquito carrying the virus. On average, only about 2 in 10 people who are bitten by an infected mosquito will actually become ill.

For those who do become ill, West Nile Virus infection can cause a relatively mild illness called West Nile Fever, characterized by fever, muscle aches, rash and headache. More severe West Nile illness is less common, but can include meningitis (inflammation of the membrane surrounding the brain) and encephalitis (inflammation and swelling of the brain itself). People of all ages are susceptible to West Nile infection, but people over age 50 are at greater risk of developing severe illness.

For prevention tips and updates on West Nile Virus activity in Chicago, visit  www.cityofchicago.org/health.  For an expert national perspective on West Nile Virus, visit the Centers for Disease Control and Prevention (CDC) on the Internet at www.cdc.gov/ncidod/dvbid/westnile/index.htm.

The material being used to control the adult mosquitoes, Zenivex, will be applied at a rate of 1.5 fluid ounces per acre. It is approved for use by the U.S. Environmental Protection Agency and is used to control mosquitoes in outdoor residential and recreational areas.

While the spray is not harmful to people or pets and is routinely sprayed in residential areas across the nation, residents of targeted neighborhoods may choose to stay indoors and close their windows while spraying is underway, as an extra precaution.

The Northern House mosquito, Culex pipiens, is the primary carrier of West Nile virus. This mosquito species thrives in water with high organic content, such as that found in catch basins (storm sewers). 

West Nile Disease, Reported Cases in Chicago:

2002      225 cases, 22 fatalities

2003      4 cases, 0 fatalities

2004      6 cases, 1 fatality

2005      41 cases, 1 fatality

2006      29 cases, 1 fatality

2007      11 cases, 0 fatalities

2008      4 cases, 0 fatalities

2009      1 case, 0 fatalities

2010      1 case, 0 fatalities

2011      8 cases, 0 fatalities

 

 # # #