September 6, 2011
City to Spray Insecticide Wednesday To Kill Mosquitoes on Northwest Side
Targeted Effort Fights West Nile Virus
For Immediate Release
Contact: Jose M. Muñoz, 312-747-9443
City officials announced today that they are stepping up efforts against West Nile virus by spraying to kill adult mosquitoes in a portion of the Northwest side of Chicago.
“CDPH monitors west-Nile activity throughout the city, when our mosquito traps indicate that the West Nile virus may threaten human health in a community, we take decisive action promptly,” stated Chicago Department of Public Health (CDPH) Commissioner Bechara Choucair, M.D.
Spraying will occur in the Norwood Park neighborhood, where CDPH traps recently yielded mosquitoes carrying West Nile virus. The area to be sprayed is bounded by Devon on the north, Northwest Highway and Nagle on the East, the villages of Harwood Heights and Norridge on the south, and Cumberland and the village of Park Ridge on the west. (Editor: map attached.)
Weather permitting, the spraying will begin at about 8:00 p.m. Wednesday, September 7, 2011 and continue for about four to five hours, with licensed mosquito abatement technicians in trucks dispensing an ultra-low-volume spray.
Spraying will occur starting at dusk, the peak period of activity and exposure of the Northern House Mosquito, the type of insect that spreads the West Nile Virus.
The material being used to control the adult mosquitoes is a permethrin-based product called Permanone 4-8. Permethrin is a synthetic chemical similar to the natural insecticide pyrethrum. This product will be applied at a concentration of 0.0035 pounds of permethrin 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.
The spray will be applied by technicians from Vector Disease Control Inc., 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 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.
“Spraying to kill adult mosquitoes is a sensible and effective component of an integrated pest management program. We spray when we have clear evidence that the West Nile Virus has made significant inroads into a community,” added CDPH Environmental Health Director Cort Lohff, M.D. “And while no one can control the weather—and in a city of 228 square miles we can't prevent every single mosquito from hatching and biting, it is our expectation that this effort, by further limiting the mosquito population, will prevent cases of human illness in Chicago.”
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). Consequently, a hot, dry summer increases the risk of West Nile virus infection, exactly the opposite of what many people believe.
In contrast, the swarms of mosquitoes most people currently are experiencing are Aedes vexans, which is a common "floodwater" mosquito that appears after heavy rains. This mosquito may be a nuisance, but they rarely are infected with West Nile Virus. Therefore, although the number of mosquitoes has significantly increased in recent weeks, the risk of WNV transmission outside the current spray zone has not.
In 2010, some 1041 human cases (57 of them fatal) of West Nile-related illness were reported nationally. In Illinois, there were 61 human cases (4 of them fatal).
Thus far in 2011, some 104 cases (four fatal) have been reported nationally. In Illinois, five human cases have been reported and the virus has been detected in a total of 15 counties.
CDPH officials ask all Chicagoans to take precautions to protect themselves and their families from mosquito bites. Especially important is the use of insect repellant containing DEET, Picaridin, or Oil of Lemon Eucalyptus.
Northern House mosquitoes are not aggressive, and people rarely notice when being bitten
In addition to using insect repellant to avoid bites, CDPH officials advise:
- Consider limiting outdoor activity after dark (dusk to dawn), which is when Northern House Mosquito is most active.
- When outside, 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;
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.
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 5 cases, 0 fatalities
2011 2 cases, 0 fatalities
The summer is over. Why bother spraying for mosquito's now?
ReplyDeleteStop using chemicals. It all ends up in our drinking water. Oh, that's right, the big D machine says don't worry about that.
ReplyDeleteMosquitoes live wel into the Fall. Autumn is when most mosquitoes mate.
ReplyDeleteWill winter bring an end to West Nile-carrying mosquitoes?
Yes and no. Like snakes and amphibians, insects are cold-blooded, and cannot regulate their own body temperatures. Because they are dependent upon their environment to maintain a sufficient body temperature, mosquitoes "disappear" in regions subject to cold winters. Female mosquitoes that survive into the onset of winter can go into hibernation; if they mated in the fall, they can emerge ready find the first available blood meal, and then lay their eggs, in the spring. Some mosquito species can lay eggs which survive extreme weather, such as cold, ice, and drought. Moisture produced by spring rains and melting snow and ice will cause these eggs to hatch, and the mosquitoes will progress through larval, pupal, and finally adult stages to begin the cycle anew.
The whole city should be sprayed to get rid of the pests, and I mean the 2 legged ones
ReplyDelete