The Sweetwater-Nolan County Health Department is urging people to take precautions to reduce the risk of contracting West Nile virus, a mosquito-borne illness.
What is it?
West Nile virus is a virus commonly found in Africa, West Asia and the Middle East. It is not known how long it has been in the United States, but the Centers for Disease Control and Prevention (CDC) believe the virus probably has been in the eastern United States since early summer 1999. It is closely related to St. Louis encephalitis virus found in the United States. The virus can infect humans, birds, mosquitoes, horses and some other animals.
How can I reduce my risk of getting West Nile virus?
Preventing mosquito bites is the best way to avoid getting West Nile virus. Remember the “Four Ds” of DEET, Dress, Dusk and Dawn and Drain:
1. Apply insect repellent that contains DEET (N, N-diethyl-m-toluamide) or Picaridin (KBR 3023, Chemical Name: 2-(2-hydroxyethyl)-1-piperidinecarboxylic acid 1-methylpropyl ester). Be sure to read label instructions. Spray clothing with repellent as well as exposed skin.
2. Dress in long sleeves and long pants when you are outside.
3. Stay indoors at dusk and dawn, times when infected mosquitoes are most active.
4. Drain standing water in your backyard and neighborhood; old tires, flowerpots and clogged rain gutters are mosquito-breeding sites.
What are the symptoms?
Most people infected with West Nile virus will not have any signs of illness. Twenty percent of people who become infected will have mild symptoms such as fever, headache, body aches and occasionally a skin rash on the trunk of the body and swollen lymph glands.
The symptoms of severe infection (West Nile encephalitis or meningitis) include headache, high fever, neck stiffness, stupor, disorientation, coma, tremors, convulsions, muscle weakness, vision loss, numbness and paralysis. Only about one out of 150 people infected with West Nile virus will develop this more severe form of the disease.
People usually develop symptoms of West Nile virus three to 14 days after they are bitten by an infected mosquito. Symptoms of mild disease may last a few days. Symptoms of severe disease may last several weeks, although neurological effects may be permanent. Rarely, death can occur.
How is it spread?
Usually, West Nile virus is spread by the bite of an infected mosquito. Mosquitoes become infected when they feed on infected birds. Once infected, mosquitoes can infect people, horses, many types of birds and some other animals. In a very small number of cases, West Nile virus has been spread through blood transfusions, organ transplants, breastfeeding and even in pregnancy from mother to baby. It is not spread through casual contact, such as touching or kissing a person with the virus.
Who is at risk for West Nile virus?
People over 50 years of age have the highest risk of severe disease. It is not known if people with weakened immune systems are at an increased risk for West Nile virus. All donated blood is checked for West Nile virus before it is used. The risk of becoming infected through blood transfusions and organ transplants is very small and should not prevent people who need surgery from having it. The risk that West Nile virus may present to an unborn baby or infant who is breastfeeding is still being evaluated. If you have concerns, talk with your health care provider.
How is West Nile virus treated?
There is no specific treatment for West Nile virus infection. In severe cases, intensive supportive therapies are indicated, such as intravenous fluids and medicine to control fever or pain. Antibiotics may be given for any secondary bacterial infection.
Can I be vaccinated for West Nile virus?
Currently there is no West Nile virus vaccine for humans, but several companies are working toward developing a vaccine. West Nile virus vaccine is available for use in horses. Horse owners in the United States are encouraged to check with their veterinarian to arrange for vaccination of their horses against this virus.
Is this a seasonal virus?
West Nile encephalitis cases usually occur in the late summer or early Fall. However, Texas has a variety of climates and when temperatures are mild, West Nile virus can be transmitted year round. It is best to try to protect yourself all year.
How likely am I to be bitten by an infected mosquito?
Fewer than one percent of those bitten by infected mosquitoes become severely ill. If you have the symptoms mentioned in this article, contact your health care provider.
Where can I get more information?
Contact your local health department (325-235-5463). West Nile virus information can be found on the Texas Department of State Health Services web site at http://www.dshs.state.tx.us/idcu/disease/arboviral/westNile/  and the CDC Web site at http://www.cdc.gov/ncidod/dvbid/westnile/index.htm .