/Plan Ahead for West Nile Virus Season

Plan Ahead for West Nile Virus Season

March 14, 2007

LAS VEGAS – The Southern Nevada Health District’s annual West Nile surveillance program will gear up for the 2007 season this month. Property owners are urged to begin to eliminate mosquito breeding sources during the winter and early spring to decrease the mosquito population. In 2006, Nevada had a total of 123 human cases of West Nile virus, including one death. Three Clark County residents contracted the illness this past summer, all of whom contracted it while traveling outside of the area. For more information or to report mosquitoes, “green” swimming pools or stagnant water sources, visit the health district website at www.SouthernNevadaHealthDistrict.org or call the mosquito control hotline, (702) 759-1220.

“The best way to control the mosquito population is to be vigilant and conscientious about breeding sources. This is the most important measure we can take to limit the spread of mosquito-borne illnesses such as West Nile virus,” said Dr. Lawrence Sands, assistant health officer. Mosquitoes need only about one cup of water to breed.

The health district’s environmental health specialists routinely survey and treat known breeding sources for mosquitoes and trap them for identification. In addition, they are tested for West Nile virus, Western equine encephalitis and St. Louis encephalitis.

Stagnant water sources are the optimal breeding source for mosquitoes. There are 17 mosquito species in Southern Nevada, however, only a few are known to “feed” on humans and horses and carry disease. The health district recommends the following strategies to eliminate standing water:

Swimming pools:

  • Keep pool covers tightly sealed
  • Remove rain water from pool covers
  • Stock “out-of-order” pools with mosquito fish
  • Change water weekly in wading pools
  • Store wading pools indoors when not in use
  • Store wading pools upright

Ornamental pools

  • Stock with fish
  • Avoid spraying with garden insect sprays
  • Remove leaves and thin out plants
  • Keep water levels up and keep water clean
  • Screen the inlet of the recirculation pump
  • If not in use, break holes in the bottom and refill with sand

Standing water sources

  • Repair leaky plumbing under and around the house
  • Prevent seepage from garden irrigation
  • Divert storm water away from foundations
  • Drain the air conditioner outlet
  • Clean rain gutters
  • Remove and dispose of all unused containers that collect water
  • Change water weekly in rooting plant containers
  • Usable containers should be stacked upside down

West Nile virus made its first appearance in the United States in the late 1990s in New York and has since spread across the country. The disease first appeared in Nevada in 2003. In 2006, there were 3887 confirmed human cases of West Nile in the United States; 120 deaths were reported.

West Nile virus is spread through the bite of infected mosquitoes, which acquire the virus by feeding on infected birds. The illness is not spread person to person.

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The Southern Nevada Health District serves as the local public health authority for Clark County, Boulder City, Henderson, Las Vegas, Mesquite and North Las Vegas. The agency safeguards the public health of the community’s residents and visitors through innovative programs, regulations, and initiatives focused on protecting and promoting their health and well-being. More information about the Health District, its programs, services, and the regulatory oversight it provides is available at www.SNHD.info.