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How to Prevent Harmful Infections

Preventing West Nile Virus

©2006 Publications International, Ltd. Thankfully, only a small percentage of mosquitoes are infected with West Nile virus.

The West Nile virus is unique in that it is typically transmitted through infected mosquitoes. On this page, you can gather tips to defend yourself against this harmful virus.

West Nile Virus Information


West Nile disease is caused by the West Nile virus, which is usually spread by the Culex species of mosquitoes. The name comes from the area around the Nile River in Uganda, where the virus was first isolated.

Wild birds are the main source of West Nile virus. When mosquitoes feed on infected birds, they become carriers and transmit the virus to people and other animals. The West Nile virus enters the bloodstream through a mosquito bite, then multiplies and spreads and can eventually make its way to the brain, where it causes inflammation.

In very rare cases, West Nile virus has been transmitted from mother to baby during pregnancy, through breast milk, and through organ transplants and blood transfusions from an infected donor. West Nile virus does not otherwise spread from person to person.

Only a very small percentage of mosquitoes are actually infected with West Nile virus, and not everyone bitten by an infected mosquito will become sick. The good news is if illness does occur, the body can usually fight it off, and many people will have no symptoms.

In those who do develop a more severe form of illness, the symptoms of fever, headache, muscle aches, swollen glands, and joint pain subside within several days. In rare cases, West Nile virus can cause encephalitis (inflammation of the brain) and meningitis (inflammation of the membranes that surround the brain and spinal cord). No preventive vaccine is available for West Nile virus.

Who's at Risk for West Nile Virus?

Anyone who comes into contact with infected mosquitoes can contract West Nile virus, but people 50 and older or those who have weakened immune systems are most at risk for complications. West Nile virus has been found in all lower 48 states, but those who live in warmer climates are more likely to encounter infected mosquitoes. People who work outdoors also have a greater chance of being bitten by an infected mosquito. Many state health department Web sites have information about West Nile prevalence within their borders.  

Defensive Measures Against West Nile Virus

To keep West Nile virus away, you need to keep mosquitoes away. Wearing insect repellent is just one of the many things you can do to protect yourself from West Nile virus:

  • Buy the right bug spray. When you reach for a can of insect repellent, be sure it includes oil of lemon eucalyptus or chemicals such as picaridin, permethrin, or DEET. DEET is toxic, so it should be applied sparingly to the skin. Don't apply a repellent that is more than 30 percent DEET on children, and never put it on their hands.
  • Wear a layer of protection. When outside in heavy mosquito areas, wear long sleeves, long pants, and socks. Mosquitoes can bite through thin fabrics, so spray clothing with insect repellent.
  • Steer clear of standing water. Standing water, whether in a puddle, a wading pool, a birdbath, clogged gutters, or a tire swing, is the mosquito's version of a hot nightclub. Get rid of the water and you get rid of the mosquito breeding ground.
  • Shield the stroller. If you are taking your baby on a walk, use a mosquito net. There are many types available for nearly any make and model of stroller or carriage.
  • Watch the time. If you are outdoors in the early morning or early evening, you're more likely to get bitten because more mosquitoes will be buzzing around.
  • Keep the outside out. Check the screens on your home's windows and doors. If they're in good shape, mosquitoes won't be moving in.
  • Make the call. If you come across a dead bird, call your local health authorities. Whatever you do, don't touch it with your bare hands. It's important to keep a firm handle on West Nile virus activity even before it affects humans, and the information you provide can alert authorities to the need for better mosquito control.
  • Put away your credit card. Ignore those infomercials about "ultrasonic" mosquito devices or cases of vitamin B. The CDC says these aren't effective in preventing mosquito bites.

Oddly enough, often the largest breeding ground for infection is the place you go to get well -- the hospital. See the next section for prevention tips against hospital infections.This information is solely for informational purposes. IT IS NOT INTENDED TO PROVIDE MEDICAL ADVICE. Neither the Editors of Consumer Guide (R), Publications International, Ltd., the author nor publisher take responsibility for any possible consequences from any treatment, procedure, exercise, dietary modification, action or application of medication which results from reading or following the information contained in this information. The publication of this information does not constitute the practice of medicine, and this information does not replace the advice of your physician or other health care provider. Before undertaking any course of treatment, the reader must seek the advice of their physician or other health care provider.