West Nile Virus Was Cause of New York Outbreak
December 1999 -- The West Nile virus was first found in Uganda in 1937. It occurs with some frequency in parts of Africa and Asia and infrequently in Europe and the Middle East. (In 1996, the West Nile virus caused 90,000 cases of fever and 17 deaths in Romania.) The West Nile virus had never been seen before in birds, less in people in the Western Hemisphere.
Sequencing of the genome of viruses isolated from birds that had died in the Bronx Zoo and from people who died with West Nile-like fever confirmed that the virus that caused the 1999 outbreak of human encephalitis in New York was, indeed, the West Nile virus. The results were reported in two articles in the journal Science (vol. 286, pp. 2331-2337, 1999).
This is the first documented vist of this virus to the shores of the U.S. and an excellent example of dangerous disease agents traveling great distances today.