West Nile Virus

What is West Nile Virus? West Nile virus (WNV) is a mosquito borne virus that can cause encephalitis (inflammation of the brain) or meningitis (inflammation of the lining of the brain and spinal cord). It affects primarily birds, humans and horses.

How is West Nile Virus spread?

The virus is spread when a mosquito becomes infected by biting a bird that carries the virus. WNV is spread to humans by the bite of an infected mosquito. Human illness is rare even in areas where the virus has been reported. The chance that any one person will become ill from a mosquito bite is low.

How can I protect myself from West Nile Virus?

  • Apply insect repellent containing DEET when outdoors, especially during dawn or dusk
  • When possible, wear long sleeves, long pants and socks
  • Drain standing water from around your house
  • Check the screens on your home to make sure they fit properly

What do I do if I find a sick or dead bird?

Dead and sick bird reporting is an important component to surveillance efforts being conducted by the Nevada Department of Agriculture. Susceptible birds are an early warning system for WNV activity and indicate the risk level of human and horse exposure.

The following birds are being tested for WNV:


  • American Crow,
  • Black Billed Magpie,
  • Common Raven,
  • Greater-tailed Grackle,
  • Pinion Jay,
  • Stellar’s Jay,
  • Western Scrub Jay


  • Barn Owl
  • Great Horned Owl


  • American Kestrel
  • Bald Eagle
  • Common Nighthawk
  • Cooper’s Hawk
  • Golden Eagle
  • Northern Goshawk
  • Red-tailed Hawk
  • Swainson’s Hawk
  • Rough-legged Hawk
  • Turkey Vulture

Upland Game Birds:  

  • Sage-grouse
  • Blue grouse
  • Quail

NDOW is particularly interested in any reports of sick or dead upland game birds.

Sick birds

Clinical symptoms in these birds include excessive wing flapping, difficulty flying and other signs of central nervous system disorder. If you observe sick corvids, owls, raptors, or upland game birds, please call the Nevada Department of Agriculture to facilitate pickup of sick live birds. Please do not handle sick birds. They can severely injure people who have not been trained to handle wildlife.

Dead Birds

Please contact the Nevada Department of Agriculture so proper submission of samples can be arranged and pertinent information obtained. Be prepared to provide the following information:

  1. Your name, address and phone number.
  2. The exact location of the bird, species, the number of birds involved.
  3. Symptoms observed, if any.

Following are some sources of more detailed information on West Nile Virus:

Surveillance and Veterinary Services

  • Nevada Department of Agriculture
    Reno (775) 688-1180 extension 231 
Las Vegas (702) 383-1251 
Carson City (775) 887-2190

  •  USGS National Wildlife Health Center 

Human Health