Jennifer WhitakerCity of Lewisville Resident

Jennifer WhitakerBachelor of Science in Chemistry from

University of North Texas7 years experience in Aquatic Toxicology lab

located in Denton Texas8 years experience with Trinity River

Authority Chemistry and Aquatic Toxicology laboratories

Combined Experience of 15 years in environmental issues

West Nile Virus Infection RoutePassed on to mosquitoes via blood from

infected birdsVirus then multiplies in the mosquitoes body

for a couple of days and ends up in the salivary glands of the mosquito

The virus is then passed from the infected mosquito to the bitten organism

Other animals infected include cats, dogs, bats and livestock

Spraying: Least Effective MeasureMust be applied directly to mosquitoes in

order for the pesticide to work. Only about 10% of organisms are affectedMost effective when applied to wings per the

DuetTM Resource GuideOnly effective on adult organismsLife span of mosquito is two weeks, so

multiple applications are typically necessary

Toxic to Natural PredatorsDuetTM Dual Action AdulticideCurrently used in Dallas CountyConsidered for use in Denton CountyChemical Makeup: View MSDS View Product Label

Do not apply to bodies of waterExtremely Toxic to Aquatic Organisms

Many aquatic species feed on mosquito larvae and eggs such as Dragonfly larvae and Gambusia affinis (Mosquito fish)

Natural SelectionNot all mosquitoes exposed to the pesticide

will die due to genetic variations that make them immune.

Mosquitoes only have a two week life span which allows for adaptation to occur rapidly

Use of more potent or toxic pesticides will be necessary to achieve the same outcome over time.

Possible Human Health Effects-Short TermSection V: Health Hazard Data of the MSDS

for DuetTM

Harmful if swallowedCan cause skin irritation; burning or prickling

sensation in eyes, nose and mouthMay cause temporary tearing, irritation and

blurred visionExcessive inhalation of mists can cause nasal

and respiratory irritation (Note: This is an issue especially for asthmatics)

Long Term Health EffectsLong term exposure to chemical pesticides

have been shown to effect the immune systemLeading to allergiesIncrease in auto immune disease such as

cancer and lupusImpaired Immune system leads to more serious

cases of WNVNote: Long term effects of the use of DuetTM

have not yet been determined.

WNV SymptomsMild Case: fever, headache, body ache, skin

rash, swollen lymph nodesSevere case (neuroinvasive): Severe

Headache, neck stiffness, stupor, disorientation, coma, tremors, convulsion, muscle weakness and paralysis. Rarely death

Source: TDSHS West Nile Fact Sheet

WNV StatisticsOnly 20% of infected people experience mild

symptoms –which means that 80% of infected people have no symptoms at all.

Less than 1% of infected people experience severe symptoms

Only 1118 WNV cases reported currently in the United States for 2012

47 of the reported cases have resulted in death

Let’s look at the Real numbersCurrent Population of U.S: 314,242,000

Only 1118 WNV documented (<0.0004 % of population)

Only 47 deaths documented (<0.0002% of population)

Current Denton County Population:686,406-Only 119 WNV cases documented (<0.02% of population)-Only 1 Death documented (0.0001% of population)

Information gathered from CDC and Denton County Health Website-current 2012 statistics

Remember DDT?The use of chemical pesticide DDT was

widely used in urban aerial sprays to control urban mosquito, gypsy moths, Japanese beetle and other insects in the 1940’s. By 1972, DDT was banned from the United States due to widespread development of resistance to DDT and evidence that DDT use was increasing preterm births and also harming the environment.

Long Term Approach for LewisvillePublic Education is Key

Provide information on City websiteInformation sent home to parents via school

systemInformative flyers placed in prominent public

locations

Long Term Approach for Lewisville Information must emphasize the 4 D’s for

mosquito controlDEET: apply insect repellent to clothes and

skin before going outdoorsDress: when weather permits wear long

sleeves and pants when outdoorsDawn and Dusk: Stay indoors at these times

during which mosquitoes are most activeDrain: Standing water is a breeding ground for

mosquitoes.