Introduction to the West Nile Virus

The West Nile Virus is a flavivirus, or neuroinvasive disease that affects the nervous system of infected people. It is found throughout West Asia, Africa, the Middle East, and since 1999, the Western Hemisphere. West Nile Virus is transmitted through the bite of mosquitoes that have been infected by biting birds carrying the virus. It is a seasonal threat in North America, coinciding with the life cycle of mosquitoes, typically spiking from summer to fall.

The West Nile Virus was first discovered in the Eastern United States, but has steadily spread and established itself in other regions. In 2005, 3000 people in the US were infected, 119 of which died from the virus. At highest risk of developing serious symptoms of the disease are people over 50. Fortunately, only one in 150 infected people have serious symptoms, which include headache, stiff neck, muscle weakness, high fever and paralysis. Of the remaining people who contract West Nile Virus, 20% experience mild symptoms such as fever, aches and pains, vomiting, and rash. 80% of those infected will have no symptoms at all. Duration of West Nile Virus depends on the severity of the infection, lasting from a few days to several weeks.

Many people mistakenly believe that West Nile Virus can be transmitted by touch. Most often, it is transmitted solely by mosquito, although there have been rare instances of transmission through breastmilk and blood transfusion. Prevention is the best way to combat West Nile Virus, and there are several steps you can take to avoid getting bitten by an infected mosquito.

Mosquitoes are at their most active during the hours of dawn and dusk, so avoiding outdoor activities at this time can help you avoid getting bitten. Wear long sleeves and long pants, and apply insect repellent. Most experts recommend a formula that contains DEET. Be sure that the screens on your house fit the window frames well, and are in good repair. Any standing water outside your house should be drained, or treated with chemicals to kill mosquito larvae. Check with your city or county to see if they have a program in place to treat public areas for mosquitoes.

Since birds are the origin of West Nile Virus, local health department officials ask that citizens who find dead birds not handle them, but instead to notify the local office. They may want to collect the bird and test it for the virus. This will give officials an indication if there is an outbreak in your area.

Written by O. Wallace

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