The West Nile virus: its recent emergence in North America

West Nile fever emerged in New York in the summer of 1999 when seven people , several horses and thousands of wild birds died. It was soon established that the human disease and the mortality of birds were related. Continued s urveillance detected West Nile virus in mosquitoes, birds, horses, small ma mmals, bats and humans, and has shown its spread to several northeastern st ates. These events confirm the establishment of West Nile virus endemically in the United States. (C) 2001 Editions scientifiques et medicales Elsevie r SAS.