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    Infectious Disease Prevention Section
    Mail Code: 1927
    PO BOX 149347 - Austin, TX 78714-9347
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    Austin, TX 78714

    Phone: (512) 776-7676
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West Nile Virus West Nile Virus
(West Nile Virus, WNV, WestNile)
ICD-9 066.4; ICD-10 G93.3

West Nile Virus Questions

West Nile Virus (WNV) School Fact Sheet

Where Has It Been And Where Is It Going?
West Nile virus (WNV) is commonly found in Africa, Eastern Europe, West Asia, and the Middle East. It was first detected in the United States in 1999, during which time there was an outbreak in New York. By mid-June of 2002, it had traveled westward to Texas. Since then, it has been reported in mosquitoes, birds (such as blue jays and crows), horses, and humans in Texas. There has also been a continued westward movement of the virus.
What Are The Symptoms Of West Nile Virus?
Most people infected with WNV have no symptoms. A minority develop meningitis or encephalitis, which can be fatal. Symptoms include fever, weakness, headache, and altered mental status. Skin rash, lymphadenopathy, conjunctivitis, abdominal pain, cough, dyspnea, and diarrhea may also be present.
Can It Be Treated?
There is no specific treatment for WNV infection. In a serious case, a person may have to be hospitalized and given supportive treatment along with good nursing care.
How Is It Spread?
West Nile virus is spread by the bite of an infected mosquito. There is no recorded proof of it being passed from person-to-person, animal-to-animal, or animal-to-person.
Can Animals Be Infected With WNV?
Yes. However, the only domestic animals that appear to be harmfully affected by WNV are equines, such as horses. Wild birds can also develop severe signs of the disease and may die.
How Should Schools Decide On Protocols Pertaining To WNV?
In areas where mosquitoes may be infected, very few mosquitoes will actually be carriers of the virus. Additionally, only a very small percent of people bitten by infected mosquitoes will show symptoms of any disease. The virus is transmitted in multiple species of mosquitoes; depending on the species, some mosquitoes feed at night while others feed during the day. Decisions on protocols for addressing prevention of WNV in schools fall under local jurisdiction; that is to say, school districts must set their own policies.
How Can Chances Of Getting Infected Be Reduced?
A few general prevention tips for WNV and other types of mosquito-borne encephalitis include:
  1. Wear long-sleeved shirts and long pants whenever you are outdoors.
  2. Apply insect repellents, such as products containing DEET, sparingly to exposed skin. Repellents may bother the eyes and mouth, so try to not apply them to the hands of children. Do not allow young children to apply repellents. Do not apply products containing DEET on children less than 2 years of age.
  3. Spray clothing with insect repellents, as mosquitoes may bite through thin clothing.
  4. Whenever you use an insect repellent, read and follow the directions for use that are printed on the product label. The Environmental Protection Agency has concluded that, as long as consumers follow label directions and take proper precautions, insect repellents containing DEET do not present a health concern since exposure to DEET is expected to be brief.
  5. It does not appear that a person can get WNV from handling live or dead infected birds. However, use gloves or double plastic bags when handling any dead animals, including birds.
  6. Make sure any windows left open have screens on them; make sure the screens are in good repair.
  7. To minimize mosquito breeding sites, remove containers of any size that would allow water to collect or change the water in them daily. Cover trash cans and remove trash.
Additional information on WNV can be found at the Texas Department of State Health Services Zoonosis Control Group’s website at  idcu/disease/Arboviral/westnile
Information on mosquito repellents is available at



Last updated September 16, 2013