Mosquitoes are common this time of year, but sometimes their bite gives you more than just an itch – a mosquito bite can give you the West Nile virus.
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Mosquitoes spread the West Nile virus. They become infected after feeding on birds that carry the virus. When the infected mosquitoes bite a person, the virus is transferred to the human via the insect’s saliva.
West Nile outbreaks have occurred every summer in the United States since 1999 and in every state except Hawaii and Alaska.
Many don’t get sick
However, the virus doesn’t make many people sick. The U.S. Centers for Disease Control and Prevention say that 70 percent to 80 percent of people infected with West Nile virus do not develop symptoms.
“The vast majority of people don’t even know that they contracted the West Nile virus because we don’t get sick,” says infectious disease specialist Alan Taege, MD.
About one in five infected people will develop a fever with other symptoms such as headache, body aches, joint pain, vomiting, diarrhea, or rash, Dr. Taege says. Most people with this type of West Nile virus disease recover completely, but fatigue and weakness can last for weeks or months.
A few people – less than 1 percent of those infected with the virus – will develop a serious neurologic disease such as encephalitis or meningitis, which is inflammation of the brain or surrounding tissues, Dr. Taege says. Recovery from severe disease may take several weeks or months, with some of the neurologic effects being permanent.
Most people, however, will simply develop immunity to the virus and never develop a West Nile illness, Dr. Taege says.
Expanding red area
Symptoms of a West Nile virus illness start to develop between three to 14 days after a mosquito bite.
“If you’re starting to run a fever and you have this expanding red area around where you believe you were bitten by a mosquito – talk to a physician,” says Dr. Taege. “If a family member notices your behavior becomes peculiar or you start to vomit, you should seek help immediately.”
There are no vaccines or treatment for the virus. You can use over-the-counter pain relievers to reduce fever and relieve some symptoms. Those with milder symptoms typically recover on their own, although some symptoms may last for several weeks. People with more severe symptoms need to be hospitalized to receive supportive treatment such as intravenous fluids and pain medications.
Reduce your risk
You can reduce your risks of contracting West Nile by protecting yourself from mosquitoes.
- Avoid going outside from dusk until dawn when mosquitoes are most active.
- Get rid of standing water around your house or apartment – wet, murky areas are where mosquitoes tend to breed. Buckets, discarded tires, and even bird baths are great places for mosquitoes to lay eggs.
- Wear long-sleeves and long pants if you’re going to be outside for an extended period of time. Dusk through dawn is when mosquitoes are most active.
- Use insect repellant that contain DEET, picaridin, IR3535 or products that contain oil of lemon eucalyptus and para-menthane-diol.
- Install or repair screens on windows and doors or use air conditioning.
“The best thing people can do, especially if they’re going to be outdoors hiking or camping, is to put on insect repellant that contains DEET,” Dr. Taege says.