Douglas County Oregon Government Portal Douglas County Health & Social Services
Douglas County Oregon Government Portal
Site Map Home Community Links    
Douglas County Health and Social Services Douglas County Health and Social Services
  Developmental Disabilities
  Emergency Preparedness
    Hospital Preparedness
    Pandemic Flu
    West Nile Virus
  Environmental Health
  Mental Health
  Public Health
  Senior Services
Emergency Preparedness
What You Should Know About West Nile Virus

Although West Nile Virus has not been detected in Oregon, it is likely to appear soon. Douglas County is working in collaboration with community partners to prepare for the arrival of West Nile Virus. Our goal is to increase community awareness about West Nile Virus through education, prevention, and surveillance.

What is West Nile Virus?

West Nile Virus (WNV) is a disease carried by mosquitoes from certain birds to people. The mosquitoes can also carry the virus from person to person. The virus was first detected in the United States in 1999 in New York City, and by October 2002 had spread to forty-four other states.
Most people infected with WNV have a mild illness with no symptoms but the virus can cause more severe illness in older people and in children. This serious illness is called encephalitis, which means an infection of the brain.

How do people get West Nile Virus?

West Nile Virus is passed to people and animals by mosquito bites. Only certain kinds of mosquitoes carry the virus and very few mosquitoes are actually infected. A mosquito gets the infection by feeding on a bird or a person that has the virus in their blood. The WNV lives in the mosquito and is passed on to a new host when the insect bites the next person or animal. The virus is most often passed from May to October when mosquitoes are in greatest numbers.

What are the symptoms of West Nile Virus in people?

Most people infected with WNV do not show any symptoms at all. Those who do become ill have symptoms of headache, body aches, nausea and often a rash or swollen lymph nodes. In a few cases the infection may progress to encephalitis.

The time between infection and the first symptoms is between 5 and 15 days. About one in one hundred fifty people infected with WNV will require hospital care. Those hospitalized will be mostly older people over 50 years of age. The death rate of those seriously ill is about 5%. There is no specific treatment for WNV, only prevention. Those who enter the hospital will get general care of diet and rest and have the staff and equipment nearby in case the symptoms of encephalitis develop.

Top of page

Which animals get West Nile Virus?


Photo of a common crow.An infected mosquito can bite any animal but only a few will get WNV. The disease infects birds, horses, and other animals as well. Wild birds are most often linked to the spread of WNV. More than 70 kinds of birds can be infected but the most severe illness is found among corvine birds. Corvine birds include crows, ravens, jays and magpies, but American crows are the birds most often found dead from WNV.


Photo of Horses.Horses also can become infected with WNV. Unlike birds, all kinds of horses seem to be equally at risk to the virus. Signs that a horse may be infected include loss of control in balance and in movement. There is a vaccine available for horses against WNV. Contact your veterinarian for additional information about WNV, the vaccine and other kinds of encephalitis that infect horses.

West Nile Virus Prevention and Control

  1. Avoid outside activity at dawn and dusk during the mosquito season [May to October]. This is particularly important for older people and children.
  2. Wear long pants and long sleeves when outside, and apply insect repellent containing Deet.
  3. Make sure that doors and windows have tight fitting screens and do not have holes or tears in them. Kill mosquitoes that have entered your house.
  4. Drain standing water on private property and clean up discarded cans, tires and containers that hold water where mosquitoes may lay their eggs. If there is a pond where mosquitoes are frequently found, stock it with mosquito eating fish called Gambusia.
  5. Make sure that gutters on the roof are not backing up with water. Each fall and spring clean gutters of leaves and any material that might cause water to back up in them.

Top of page

What is the Oregon West Nile surveillance program?

West Nile infection has not been found in any person in Oregon as of March 1, 2003. The Oregon Department of Health Services (DHS) maintains a statewide WNV program as part of a larger role to control insect carried diseases. Part of the program is to report WNV cases and test mosquitoes and animals they bite for WNV. Since birds, and particularly crows, can die of WNV, dead birds are being tested for the virus.

Encephalitis Reporting

Humans, horses and birds like emus and ostriches can get encephalitis. There are testing / reporting programs for these diseases and WNV can be sorted out from the others. These routine-testing programs will help to find the virus in Oregon.

Mosquito Testing

Mosquitoes throughout the state are sampled for the WNV and other viruses that cause encephalitis. Some counties have mosquito control agencies that monitor the types and numbers of mosquitoes. These agencies also may have spraying programs to control the mosquitoes.

Chicken Testing

The state has placed 200 special chicken flocks to study. The flocks are tested during the mosquito season to detect if WNV is present. If WNV is found, then a more active search is started and mosquito control programs are begun.

Dead Bird Surveillance

Oregon began testing of dead crows and related birds for WNV in 2002. Although no WNV was found that year, studying dead crows may help identify the virus if it enters the state. State agencies, private organizations and individuals cooperate in the program by reporting dead bird sightings.

Top of page

What should I do if I find a dead crow or jay?

There are many birds that can be infected by WNV, however crows and jays are the most more likely to be infected. Crows have all black feathers, black beaks and black feet. They are larger than other black birds, from 17 to 20 inches tall from the tip of the tail to tip of beak.
If you find a dead crow, jay, magpie or raven, do not touch it. Promptly call the number below to arrange for its pick up.

If you find a dead crow, jay, magpie or raven, do not touch it.
Call (541) 464-3820 or 1-(800) 234-0985

Where can I get more information about West Nile Virus?

For Information on Pesticide Usage

Top of page

How to Reach Us

Health Department
621 W Madrone
Roseburg, OR 97470
Phone: (541) 440-3568
Toll Free: 1-(800) 234-0985

Photo of mosquito.