When was the first North American case of West Nile Virus reported?
In 1999 in New York City. Authorities do not know how the virus reached New York City, although theories include human-transported mosquito or storm-transported bird. When does Oregon expect to see its first case of West Nile Virus? By this spring or summer. Before Jan. 1, 2002, the virus was isolated to states east of the Mississippi. Now, Oregon is among only four states in the continental U.S. to have no reported cases; the virus has been reported in Washington, Idaho and California. Fifty-four percent of U.S. cases have occurred in Illinois, Louisiana, Michigan and Ohio. What are the symptoms? Eighty to 90 percent of cases result in no illness or only mild symptoms. In 10 percent to 20 percent of cases, the symptoms are a flu-like illness with abrupt onset of symptoms such as fever, headache, sore throat, backache and muscle aches. In one case out of 150, the result is meningitis or encephalitis. The incubation period is five to 15 days. Who is most at risk? The high-risk groups ar
