Official website for the City of Aurora, Illinois. Mayor Robert J. O'Connor

“Help Fight the Spread of West Nile Virus”

  • By Albert J. Dennis
  • Housing Inspector Coordinator
  • City of Aurora, Illinois

The Centers for Disease Control reported 884 human cases of West Nile virus in the State of Illinois in 2002. Sixty-four cases resulted in death. 284 people died from West Nile virus nationwide in 2002 [1]. West Nile virus is an encephalitis virus transmitted by a stagnant water type of mosquito known as Culex pipiens.

Stagnant water mosquitoes lay their eggs directly on the water surface. The reproduction sources are constantly replenished with the next generation’s eggs, resulting in constant emergence of new adults [2]. The deadliest mosquitoes are of the stagnant water variety as opposed to the bothersome and prolific floodwater mosquitoes that appear after rainfall.

Floodwater mosquitoes lay their eggs on dry ground in areas that are prone to flooding. The eggs lay dormant until inundation occurs initiating hatching. These annoying little devils are picnic and camping spoilers but don’t carry malaria or West Nile virus.

Property owners and tenants can actively help stem the spread of West Nile virus by eliminating places where stagnant water mosquitoes produce offspring on property sites. It takes very little stagnant water for this type of mosquito to lay its eggs in. Remove these sources of water collection and you remove the mosquito’s ability to reproduce.

Where are potential stagnant water mosquito breeding spots on properties? A classic of course is a discarded tire. Similar mosquito nurseries are cans, jars, bottles, plastic containers, ceramic pots, open barrels or other water-holding containers. Beer and pop cans are more than just eyesores. Unused flowerpots aren’t as ugly as littered beer cans, but if they contain stagnant water, mosquitoes will lay eggs in them. Containers buried by overgrown vegetation must not be overlooked.

Water in birdbaths will serve mosquitoes well if it is not emptied weekly and replaced with fresh water. Tire swings should be emptied and have drain holes drilled through them so water won’t collect. Recycle containers likewise need holes drilled in the bottom of them if they are stored outside. Plastic wading pools should be turned over or stored out of the weather when not in use. Wheelbarrows should be overturned if they are stored outdoors.

Clogged roof gutters become wonderful mosquito birthing rooms. Besides leading to water damage to a building’s structure, stopped up gutters jeopardize public health. Flooded roof gutters can produce hundreds of mosquitoes during the warm seasons.

Hollow tree stumps and rot holes in the crotch of tree trunks should be filled in or removed if they hold water. Ornamental pools need to be aerated or stocked with fish. Water gardens may be fashionable but become major mosquito hatcheries if they are allowed to stagnate.

Boats should be stored covered or turned upside down so rainwater does not collect and stagnate. Soft covers on boats and trailers can bow from the weight of rainwater. That water must be removed before it stagnates. The same goes for covers on unused swimming pools. Unused swimming pools must be cleaned and chlorinated. A stagnant swimming pool rapidly turns into a prolific mosquito producer.

Holes and low spots in the yard ought to be filled and leveled to eliminate standing water. Drains, ditches and culverts should be kept free of grass clippings, weeds or trash so water drains properly. Any place where water stands undisturbed by current or wave action rapidly becomes fertile mosquito breeding grounds.

Illinois led the nation in 2002 in positive cases of West Nile virus and ensuing deaths. Positive cases of the virus were reported in 100 of the 102 counties in Illinois including Kane and DuPage. By maintaining our properties vigilantly each of us can do our part in the battle to eradicate this disease.

1. Centers for Disease Control - Media Relations

2. Northwest Mosquito Abatement District – Wheeling, IL