NORTHWEST MOSQUITO ABATE= MENT DISTRICT

147 W. Hintz Rd.

Wheeling, IL<= /st1:place>. 60090

Phone: (847) 537-2306

Fax: (847) 537-2583

www.nwmadil.com=

Mosquito Update=

August 31, 2006

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WEST NILE VIRUS HUMAN CASES

Currently, 39 human West Nile virus (WNV) cases hav= e been confirmed by the Illinois Department of Public Health. Currently, there are 5 human WNV illnesses reported within NWMAD territory (1-Arlington Heights, 1-Des Plain= es, 1-Mt. Prospect, 1-Palatine, 1-Prospect Heights).

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PRESENT CONTROL ST= ATUS:

NUISANCE MOSQUITO CONTROL<= /o:p>

Nuisance mosquito numbers remain low averaging (<10 female Aedes vexans) below our nuisance thre= shold of 35 female Aedes vexans per <= st1:place w:st=3D"on">New Jersey light trap. Control efforts and rec= overy from the previous 4 drought years are responsible for the low numbers. Public nuisance mosquito complaints= have been low or from isolated areas.

CULEX MOSQUITOES

Culex m= osquito numbers have decreased (averaging around 50/gravid trap) due to control eff= orts focusing on Culex production si= tes. Recent rains will once again provide additional Culex stagnant water production areas (for examples see: http://www.nwmadil.com/b= reeding sites1.htm). Residents are strongly advised to inspect & eliminate all st= agnant water areas from their properties that may produce these mosquitoes every w= eek through the months of July-September. Any container that holds water and organic debris for greater than 7 days can produce many of these mosquitoes.

Stagnant water mosquito producing sites (detention/= retention ponds, ditches, building foundations & container sources) will be treat= ed with the microbial insecticide Baci= llus sphaericus and the insect growth regulator methoprene (a.k.a. Altosid). We have completed our second treatment of street catch basins throughout the District with Altosid Ingots (methoprene).

LABOR DAY = OUTLOOK

Low nuisance and Culex mosquito numbers combined wi= th cooler temperatures and predicted rainfall Saturday evening through Labor D= ay is likely to lessen biting mosquito numbers. Because Wes= t Nile virus continues to be detected in mosquitoes throughout the NWMAD territory, residents are still advised to implement mosquito avoidance methods (i.e. u= se of insect repellents, screened windows & closed doors, avoid peak mosqu= ito biting times just after dusk and before dawn, etc) .

MOSQUITO VIRUS SURVEILLANCE IN ILLINOIS

NWMAD has tested (Vec= Test) 1237 batches of mosquitoes for West Nile Virus, St. Louis and Eastern Equine encephalitis. 372 infected ba= tches of mosquitoes have been detected thus far. We will continue to ship out sample= s for confirmatory testing by Illinois Natural History RT-PCR testing.=

The Illinois Departme= nt of Public Health (IDPH) reports: 60 counties with mosquitoes or birds testing positive for WNV.

Mosquito batches test= ing positive in the District are posted at the NWMAD website http://www.nwmadil.com/VECTEST= 1.htm.

Director’s Note:<= /b> Currently as of August 31, suburba= n Cook County human WNV cases (15) are significantly below the 2002 (67 cases) & 2005= (52 cases) outbreak years for this same time period. Though additional cases are likely to be added as pending epidemiological studies are concluded; it is = at this point in time, still unlikely to equal the 2002 & 2005 outbreak ye= ars for suburban Cook County. How= ever, a warm September may extend the human WNV infection period. Lower human cases in the “wet” 2006 mosquito season would be an insightful event possibly suggestive of: periodic rainfall events detrimental to Culex stagnant water production sources, reinforcement that hot-dry conditions (i.e. outbreak ye= ars 2002, 2005) in the Midwest favor human/bridge vector development and/or deployment, increased human and/or avian immunity to WNV, and/or improved C= ulex control by Cook County Mosquito Abatement Districts and allied private and public control agencies.

ADULTICIDING (Night Spraying Operation):

All Townships within = the NWMAD territory have been sprayed based on the detection of repetitive WNV = infected mosquito samples. To date, Townships and/or parts of Townships have been sprayed on the following dates based on infected mosquito surveillance and Culex mosquito abundance:

Barrington Township: 8/3, 8/22

Elk Grove Township: 7/13, 7/18, 7/27, 8/3, 8/7, 8/22, 8/24

Hanover Township: = 7/18, 7/26, 8/8, 8/15, 8/16

Maine Township: = 7/18, 7/26, 8/3, 8/4, 8/7, 8/15, 8/16, 8/22

Western NWMAD portion= of Village of Northbrook: 7/13, 8/4, 8/15

Palatine Township: = 7/27, 8/3, 8/8, 8/17, 8/22, 8/24

Schaumburg Township: = 7/13, 7/18, 7/27, 8/7, 8/8, 8/17, 8/24

Wheeling Township: 7/13, 7/18, 7/27, 8/3, 8/7, 8/8, 8/15, 8/16, 8= /22, 8/24

Nightly spraying sche= dules can be viewed at the NWMAD website: htt= p://www.nwmadil.com. Alternately, a recorded phone mess= age describing our scheduled nighttime spray program can be reached at (847) 537-2306 and pressing “5” on your telephone keypad.   More information regarding o= ur Adulticiding program may be viewed at: http://www.nwmad= il.com/Night Spray info1.html

REDUCING THE RISK = OF MOSQUITO BITES:

Avoid outdoor activit= y if possible from dusk to dawn when the mosquitoes bite the most. If you do go out wear light colored protective clothing and insect repellent (always read label warnings and directions). Make sure mosqui= toes do not enter homes through unscreened or broken doors or windows.   Residents are encouraged not= to create mosquito harborage areas. Make sure tall grassy areas are trimmed and other vegetation is cut back. If plants must be water= ed do so in the morning so the vegetation and soil has a chance to dry making it = less attractive to mosquitoes.    Empty any containers holding stagnating water like tire casings, birdbaths, flower pots and barrels that may produce mosquitoes. Un-maintain= ed swimming pools may produce thousands of mosquitoes. Call the District to report stagna= nt water areas that remain wet for more than 7 days. Additional mosquito avoidance/contr= ol practices may be found at the District’s website: www.nwmadil.com.

Mike Szyska

Director

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        =             &nb= sp;            =             &nb= sp;            =    Nuisance Mosquitoes

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        =              =             &nb= sp;            =             &nb= sp;     Culex Mosquitoes