West Nile Virus Information

Steps Families Can Take to Prevent West Nile Virus

El Virus del Nilo Occidental Preguntas y Respuestas

The Ventura County Environmental Health Division has established a mosquito West Nile Virus Hotline, (805) 658-4310, for residents to report potential mosquito breeding sources created from improperly maintained swimming pools and other similar water impoundments located on private property. To learn more, visit www.westnile.ca.gov

West Nile Virus Prevention To decrease exposure to mosquitoes and the WNV:

  • Avoid spending time outside when mosquitoes are most active, especially at dawn and dusk.
  • When outdoors, wear long pants, long sleeve shirts and other protective clothing.
  • Apply insect repellent according to the label instructions. DEET-containing repellents are recommended.
  • Make sure that doors and windows have tight fitting screens. Repair or replace screens that have tears or holes.
  • Click here for more information on how to reduce mosquito populations around your home.
Important Telephone Numbers and Websites

What do I do if I see a dead bird?

If you find a dead bird, particularly a crow, jay, magpie, or raven, please promptly call the California Department of Health Services (DHS) at the number shown below. Do not touch the bird. DHS will record all dead bird reports and will arrange for pickup and laboratory testing for WNV when appropriate.

Toll Free Phone: California Department of Health Services West Nile Virus HOTLINE (877) WNV-BIRD (877-968-2473)
E-mail: arbovirus@dhs.ca.gov
Website: www.westnile.ca.gov

What are the symptoms of West Nile Virus in people?

Most people who are infected with WNV have no symptoms. Those who become ill may have symptoms such as fever, headache, nausea, body aches, mild skin rash, or swollen lymph nodes. In a few cases, the disease will progress to a more serious illness such as encephalitis (inflammation of the brain) and can be fatal. The time between the mosquito bite and the onset of illness, known as the incubation period, ranges from 5 to 15 days in humans. There is no specific treatment for infection with WNV, although supportive medical care is important.

How do people and animals get West Nile Virus?

West Nile Virus is transmitted to people and animals through the bite of infected mosquitoes. Mosquitoes become infected when feeding on wild birds with WNV in their blood. Only certain species of mosquitoes carry the virus and very few mosquitoes are actually infected. Once a mosquito becomes infected, it can pass the virus on when biting a person or animal. The virus is most prevalent from May to October when mosquitoes are most abundant.

Which animals get West Nile Virus?

The disease most often affects birds, but occasionally causes disease in other animals as well.

Birds
Wild birds are the primary reservoirs of WNV in the environment. WNV infection has been reported in more than 100 bird species. Many birds infected with WNV will not appear ill, however, the virus can cause serious illness and death in some birds, especially among the corvid birds, which include crows, jays, ravens, and magpies.

Horses
Like people, most horses bitten by infected mosquitoes will not become sick with WNV. Horses that become ill may have symptoms such as stumbling, circling, hind leg weakness, inability to stand, muscle tremors, and death. A vaccine to prevent WNV illness in horses is available from veterinarians. For more information on WNV and horses, please visit www.cdfa.ca.gov/ahfss/ah/wnv_info.htm. For an informational brochure, click on WNV & Your Horse