West Nile virus, discovered in 1937 in the West Nile area of Uganda, has spread to Mediterranean and temperate parts of Europe and, now, to North America. 

Outbreaks of West Nile virus have occurred in a number of countries including Egypt, Israel, South Africa, and countries in parts of Asia and Europe. 

Recent outbreaks, outside of North America, have occurred in France and Israel in 2000, Russia in 1999, and Romania in 1996-97.

In August 2001, it was confirmed in ten dead birds found in southern Ontario. In the summer of 2002, birds in Manitoba and Quebec also tested positive of the virus.

By mid-September 2002, three cases had been confirmed in Ontario and blood samples form six other people, also in Ontario, were being tested for the disease.

Scientists with the Centers for Disease Control (CDC) believe West Nile Virus first arrived in the Western Hemisphere with an outbreak in New York City during the summer of 1999. 

August 1999 also saw the first reported death in the United States from West Nile Virus. By the end of 1999, the metropolitan New York area was hardest hit, reporting more than 60 cases of severe disease with seven deaths. Horse and bird deaths were also reported in the United States last year. 

According to latest information of CDC (Centers for Disease Control), 2,072 people have been diagnosed with West Nile virus in the United States this year. Illinois has had the most deaths, with 27. Louisiana and Michigan have had 11 each. 

Although the U.S. virus bears a genetic resemblance to strains found in the Middle East, there is no scientific conclusiveness about its origin.

West Nile is carried and spread by mosquito. It can cause fatal inflammation of the spinal cord and brain (encephalitis) in certain birds, horses and humans.