West Nile Disease
A potentially serious illness, West Nile disease is commonly found in Africa, West Asia, and the Middle East. Scientists believe that this disease has been occurring in the United States since the early summer of 1999. The virus that causes it is transmitted primarily by mosquitoes and ticks.
Most people infected with West Nile virus (about 80 percent) will not show any symptoms at all. Up to 20 percent of those infected will have flu-like symptoms. About 1 in 150 people will develop severe symptoms. At this time, there is no treatment capable of killing the virus. Therefore, preventing mosquito bites in the first place is the best way to avoid this disease.
(For a closer look at this disease, click West Nile Virus. This article discusses who is most at risk of contracting it, how it is diagnosed, and more.)