NUISANCE MOSQUITO CONTROL

Nuisance floodwater mosquito numbers are, currently, very low. Two inches of rain that fell on August 3^rd is not expected to appreciably increase nuisance mosquito numbers due to previously dry conditions. Any mosquitoes that might complete their lifecycle in remaining floodwater areas will be evident by the beginning of next week.

Crews continue to treat floodwater areas with methoprene pellets.

CULEX MOSQUITOES

Culex mosquito numbers collected from recent gravid traps have increased due warmer temperatures. Currently, we are entering a cool spell which will decrease Culex numbers in our gravid traps. Residents are still advised to inspect their properties for stagnant water areas that produce these mosquitoes. Any container that holds water and organic debris for greater than 7 days can produce many of these mosquitoes. Cooler temperatures will decrease biting activity of these mosquitoes and possibly WNV levels as we experienced in 2003. This will also change if temperatures warm up as they did in 2003 during August and September.

Crews have been treating above ground stagnant water mosquito producing sites (detention/retention ponds, ditches, building foundations & container sources) with the microbial insecticide Bacillus sphaericus.

ADULTICIDING (Night Spraying Operation):

Adulticiding (night spraying) has been performed in Northfield, Wheeling, Palatine, Barrington, Hanover, Schaumburg (in part), Elk Grove and Maine Townships due to the detection of repetitive WNV mosquito batches. Focal areas on the East end of the District were treated two or more times depending on virus surveillance and Culex mosquito abundance. WNV is now widely distributed throughout the NWMAD territory. Future adulticiding has been suspended due to cool temperatures, but, may restart pending future virus activity and favorable weather conditions.

Nightly spraying schedules can be viewed at the following website: http://www.nwmadil.com/District_map1.html. Alternately, a recorded phone message describing our scheduled nighttime spray program can be reached at (847) 537-2306 and pressing “5” on your telephone keypad. More information regarding our Adulticiding program may be viewed at: http://www.nwmadil.com/Night Spray info1.html

MOSQUITO VIRUS SURVEILLANCE IN ILLINOIS

Five human cases of WNV have been reported by the Illinois Department Public Health (see attached). Currently, 45 counties have reported WNV infection of humans/horses or birds or mosquitoes (see attached).

Mosquito pools testing positive in the District are posted at the NWMAD website http://www.nwmadil.com/VECTEST1.htm.

RESIDENTS ARE ADVISED TO PROTECT THEMSELVES FROM BITING MOSQUITOES USING REPELLENTS AND SHOULD AVOID PEAK MOSQUITO BITING TIMES!

DIRECTOR’S NOTE: Currently, WNV progression in Illinois appears to fall between 2002 and 2003 levels. This appears attributable, primarily, to normal to slightly cooler temperatures we have been experiencing in 2004. Viral intensities indicated by the VecTest, thus far have been predominantly lower; similar to 2003 levels. Residents of the NWMAD District still need to exercise caution against biting mosquitoes since surveillance indicates that WNV is still widely distributed in the mosquito population. If temperatures increase as they did in August-September of 2003 viral amplification will restart and risk of infection to humans will correspondingly increase!

DEAD BIRD SURVIELLANCE INFORMATION:

Cook County Department of Public Health reported 6 birds testing positive for WNV in the NWMAD territory. NWMAD has received 477 dead bird reports to date. Cities, villages and the public are encouraged to report dead birds to our District’s Dead Bird/Animal reporting web page, which can be accessed at www.nwmadil.com. Knowing this information allows our District to better focus our control efforts. The Cook County Department of Public Health is testing dead birds for WNV. Anyone wishing to have recently dead crows and blue jays tested for virus should phone the Cook County Department of Public Health at (708) 492-2650.

REDUCING THE RISK OF MOSQUITO BITES:

Avoid outdoor activity 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 mosquitoes 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 watered 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-maintained swimming pools may produce thousands of mosquitoes. Call the District to report stagnant water areas that remain wet for more than 7 days. Additional mosquito avoidance/control practices may be found at the District’s website: www.nwmadil.com

Mike Szyska

Director

HUMAN CASES (Courtesy of IDPH) WNV POSITIVE COUNTIES