The insecticide is designed to kill mosquitoes that may be carrying the West Nile Virus. Areas targeted are those where infected mosquitoes have been found in recent days.
Weather permitting, the spraying will begin at dusk (abut 7:30 p.m.) and continue through the night until approximately 1 a.m., with licensed mosquito-abatement technicians in trucks riding up and down streets and alleys, spraying an ultra-low-volume insecticide spray up into the air.
Here is a map of the area to be sprayed--basically from California Avenue on the east to Central Park Avenue on the west, 59th Street on the north to about 75th Street on the south.
CDPH reminds residents to take precautions against mosquitoes that may carry the virus, including:
• Use insect repellent that contains DEET, Picaridin or Oil of Lemon Eucalyptus.
• Eliminate standing water. This includes emptying water from flowerpots, gutters, pool covers, pet water dishes and birdbaths regularly.
• Keep grass and weeds short to eliminate hiding places for adult mosquitoes.
• When outside between dusk and dawn, wear loose-fitting, light colored clothing including long pants, long sleeve shirts, socks and shoes.
• Check that all screens, windows and doors are tight-fitting and free of holes and tears
• Check on neighbors regularly who may need additional assistance, including the elderly.
Each year, CDPH conducts a mosquito surveillance, prevention and control program to protect residents from West Nile virus and other diseases spread by mosquitoes.
Though mosquitoes found to carry the Zika virus are not native to Chicago, CDPH has launched a recent campaign, #StopZika, to educate residents traveling to Zika-infested regions how to protect themselves. The campaign also reminds residents how the department is working to prevent mosquito-borne viruses that are endemic to Chicago, including West Nile virus.
In addition to spraying, CDPH's mosquito abatement program includes dropping larvacide in catch basins--starting in spring--which helps limit the number of mosquitoes that can carry the virus, and regularly testing mosquitoes caught in traps throughout the city.
The material being used to control the adult mosquitoes, Zenivex™, is approved for use by the U.S. Environmental Protection Agency and has been widely applied to control mosquitoes in outdoor residential and recreational areas across the city. The spray will be applied by licensed mosquito abatement technicians from Vector Disease Control International, described by CDPH officials as a leader in the mosquito control industry. Guiding the crews through the streets will be supervisors from the Chicago Department of Streets and Sanitation.
While the spray is not believed to be 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. CDPH staff are leaving door hangers in parts of the affected areas to notify residents that the spraying will occur.
"Spraying to kill adult mosquitoes is an effective component of an integrated pest management program," added CDPH Environmental Health Medical Director Cort Lohff, M.D. "It is our expectation that this effort will further limit the mosquito population and prevent cases of human illness in Chicago."
As part of ongoing response efforts, CDPH will continue to collect mosquitoes from traps located throughout the city and test these mosquitoes for West Nile virus. Using results of these tests, CDPH will determine the appropriate steps to be taken in order to best protect Chicago residents.
West Nile virus cannot be transmitted from person-to-person. Instead, it is transmitted strictly through mosquitoes.