Public service announcement of the day...
Map of the Spread of West Nile Virus
What's West Nile Virus (WNV)?
WNV is a kind of virus that is carried by mosquitoes, which can infect humans, horses, and other mammals, in addition to birds. It is believed to have originated in the area of Western Asia, the Middle East, and Africa (hence the name).
What happens when you get WNV?
Most people don't actually develop any sort of illness from being infected with WNV.
Of those who do get sick, most will have what is called West Nile Fever (20% of all those infected). Symptoms include fever, headache, fatigue, and body aches. Sometimes there is also a skin rash over the trunk of the body along with swelling of lymph glands. In other words, it's not much worse than a case of the flu.
However, the most severe symptoms which can develop involve the nervous system. Occurring in about 1/150 people infected with WNV, these are called of West Nile Encephalitis (infection of the brain) or West Nile Meningitis (infection of the cells which form a sac around the brain and spinal cord). The symptoms of severe infection include headache, high fever, neck stiffness, tremors, convulsions, muscle weakness, and paralysis. It is also possible to develop disorientation which can progress to stupor (an state of near unresponsiveness) and even to coma.
So what do I do to avoid getting infected?
There is currently no vaccine against WNV. The best way to prevent infection is to avoid being bitten by mosquitoes.
Limit your contact with mosquitoes. Avoid being outdoors during dawn, dusk, and early evening (peak "biting times"). Wear long-sleeved shirts and long pants as well as insect repellent which contains DEET (
N,N-diethyl-m-toluamide). Note that more DEET means longer lasting protection, not better protection, and this is only true up to 50% (more than 50% DEET doesn't last any longer than 50%). Check your windows and screens to make sure mosquitoes can't get into your home.
Also, it is a good idea to reduce the places around your home where mosquitoes breed. This is pretty much any place with standing water. Empty out any flowerpots, watering cans, buckets, or similar containers at least once a week. Clean out your rain gutters and remove piles of yard waste which can accumulate moisture.
What do I do if I think I'm infected with WNV?
Go see your doctor. If she thinks you might be infected (based on your history, physical exam, and whether there is WNV in your area), there is a blood test which checks for antibodies in your blood (IgM) which are specific for WNV. However, because this test is not always definitive, a second test called the Plaque Reduction Neutralization Test (PRNT) is used to confirm the diagnosis. This test requires culture and growth of the virus, so it may take more than a week to conduct.
There is unfortunately no specific treatment for WNV yet. Current management consists of symptom management and possibly hospitalization until your body can rid itself of the virus.
Yaah! I'm so worried that I might get infected and die!
Remember that first, most people who get WNV don't get sick from it, and that the majority of those who do get sick only get the fever, not the nervous system infection. There are also lot of other diseases which mosquitoes can carry, some of which look a lot like WNV infection in addition to very common things, like a bad cold, which can have some of the symptoms listed above.
Regardless, it is most important to
protect yourself from mosquitoes, and go see a doctor if you feel very sick. Even if it's not WNV, it may be something else which requires medical attention.
For more information, refer to the CDC's page on
West Nile Virus.