/District Announces Three Human West Nile Virus Cases in Clark County Residents

District Announces Three Human West Nile Virus Cases

in Clark County Residents

September 2, 2005

Protective Actions to Avoid Mosquito Bites Urged
During Outdoor Labor Day Activities

(Las Vegas, Nev., – September 2, 2005) – The Southern Nevada Health District is reporting the first human West Nile virus cases of 2005 in Southern Nevada. Three residents of Clark County have tested positive for the virus. Details on the cases are as follows:

  • One female over 50 years of age who contracted the severe form of illness (West Nile encephalitis).
  • Two males, one over 50 years of age and one under 50 years of age, both of whom contracted the mild form of illness (West Nile fever). Based on travel history, one of these people was not infected with West Nile virus in Clark County.

“As people enjoy outdoor activities over the Labor Day weekend, it is important to practice preventive measures to avoid mosquito bites,” said Dr. Donald Kwalick, chief health officer. “Mosquitoes that carry West Nile virus remain active throughout Clark County and in neighboring counties and states,” said Kwalick.

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. The health district strongly stresses the need for individual protective actions to avoid mosquito bites:

  • Apply an insect repellent containing DEET (N, N-diethyl-meta-toluamide) according to manufacturer’s directions. Repellents containing picaridin and oil of lemon eucalyptus also have some efficacy. However, DEET is the best-studied and most-effective repellant available.
  • Wear pants and long-sleeved shirts, when outdoors.
  • Avoid spending time outside when mosquitoes are most active, notably at dusk (the first two hours after sunset) and dawn.
  • Eliminate areas of standing water, including bird baths, un-maintained swimming pools and sprinkler runoff, which support mosquito breeding.

Future updates on human West Nile virus cases will be posted to the health district website at www.southernnevadahealthdistrict.org.

For additional information on West Nile virus, including updated maps of West Nile virus positive mosquitoes, birds and horses, visit the Southern Nevada Health District website at www.southernnevadahealthdistrict.org. The public may also call the West Nile virus hotline at (702) 759-1220 with questions, concerns or to report standing water and large numbers of mosquitoes.

Visit the Media Contacts webpage for media related inquiries.


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.