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West Nile Virus Information

In September 2002, Laramie County reported its first confirmed case of West Nile Virus in a horse. Total confirmed West Nile Virus cases for 2002 in Laramie County: nine horses, reported by the Wyoming Veterinary Laboratory. There have been no human cases confirmed in Laramie County.

Program Information

Our mission in the West Nile Virus program is to take a proactive approach in mosquito control to protect the health of the public. We complete our mission through surveillance, reducing the population of mosquiteos prior to them becoming adults through the use of environmental friendly bacteria, and lots of public education.

Services provided:

  • Education
  • Surveilance
  • Mosquito Control in Public areas
  • Sale of Bactericide treatment to kill mosquitos

Frequently Asked Questions

What is West Nile virus?
West Nile virus is a disease that may cause an infection of the brain known as West Nile encephalitis. Cases of West Nile virus infection were first documented in the United States in New York City during the summer of 1999. West Nile virus was confirmed in Colorado at the end of Summer 2002.

How do people get West Nile virus?
People become infected by the bite of a mosquito infected with West Nile virus. The risk of being infected increases during times of high mosquito activity such as dusk and dawn. Individuals over the age of 50 and those with compromised immune systems have the highest risk of severe disease.

What are the symptoms of West Nile virus?
Most infections are mild and symptoms include fever, headache, body aches, and occasionally a skin rash and swollen lymph glands. Less than 1% of infections are severe and symptoms of a severe infection may include; headache, high fever, neck stiffness, disorientation, muscle weakness and tremors. People exhibiting severe symptoms of West Nile virus should seek medical attention immediately.

Can my pets get West Nile virus?
Dogs, cats, horses and other domestic pets have been known to get West Nile virus. West Nile virus infections in unvaccinated horses may cause severe or sometimes fatal symptoms in the animal. Most animals show mild if any symptoms and are expected to fully recover from the disease. There is no documented transmission from animals to humans.

Is there a vaccine for West Nile virus?
There is currently no human vaccine for West Nile virus. Contact your veterinarian for information regarding the vaccine available for horses.

How can I prevent my family from getting West Nile virus?
Prevention of West Nile virus should be approached by the dual method of using personal protection and eliminating mosquito breeding areas.

Personal Protection

  • Wear protective clothing such as lightweight long pants and long sleeve shirts.
  • Make sure doors and windows in the home are tight fitting.
  • Repair or replace any screens with holes or tears.
  • Limit outside activity during times of high mosquito activity such as the feeding times of dusk and dawn.
  • Apply insect repellant. Studies conducted by the Center for Disease Control find that insect repellant with DEET (N, N-diethyl-m-toluamide) is the most effective.
Percent of DEET in Repellant Average Time of Protection
23.8% DEET 5 hours
20% DEET 4 hours
6.65% DEET 2 hours

Remember to reapply repellent as needed or choose a repellent that provides protection for the amount of time you will be outdoors. Products with less than 10% DEET are recommended for children. Additional information about pesticides can be found at National Pesticide Information Center.

Eliminating Breeding Habitat

  • Mosquitoes require water to complete their life cycle. In warm weather mosquito larvae developing in water can become an adult mosquito in as little as 7 - 10 days. By eliminating breeding areas, the number of adult mosquitoes responsible for spreading disease should decrease.
  • Drain all standing water on your property, no matter how small the amount. Change the water in birdbaths or wading pools and empty flowerpot saucers at least once per week.
  • Keep roof gutters clear and draining freely.
  • Remove items that could collect water such as old tires, buckets and empty cans. Drill drainage holes in tire swings.
  • Do not over-water lawns and gardens to prevent standing water. I have areas on my property where standing water can not be eliminated such as retention basins, rainwater cisterns, ditches or low lying marshy areas.

How can I prevent mosquitoes from breeding in those areas?
If breeding areas can not be eliminated, a biological pesticide that uses bacteria which is found naturally in soils throughout the world can be used. Bacillus thuringiensis var. israelensis or Bti can be purchased at local farm and ranch suppliers or at the Cheyenne/Laramie Co. Health Department. Bti is very specific to mosquito, black fly and midge larvae and is not known to affect other isects, animals or humans. I have heard that West Nile virus kills wild birds.

What should I do if I find a dead bird?
Some of the surveillance efforts for West Nile virus include the monitoring and occasional testing of dead wild birds. If a dead bird is noted, contact the State of Wyoming Health Department at 877-WYO-BITE . Some birds will be collected for testing while others will only be included in the surveillance numbers.

How do I dispose of a dead bird not wanted for testing?
Wearing rubber gloves, scoop up the dead animal with a shovel and place it in a plastic bag. If you do not have gloves, insert your hand into two plastic bags, grasp the bird carefully and invert the bag over the bird. Place the bag in a tight fitting trash container.

How do I get more information on West Nile Virus?
Contact the Division of Environmental Health at 307-633-4090 or the Cheyenne or Cheyenne Weed & Pest at 307-637-6475

Related Internet Sites

Wyoming Dept of Health
Center for Disease Control