West Nile virus: surveillance activities in Canada

West Nile Virus in California

“…Since the arrival of West Nile virus (WNV, Flavivirus , Flaviviridae ) into New York City in 1999, the public health community has chronicled the unimpaired spread of this virus across North America from the Atlantic to the Pacific Coasts ( 1 ) and from Canada ( 2 ) into tropical America ( 3 ) and the Caribbean ( 4 , 5 ). Regionally, the epidemic has been characterized by an initial introduction with a few human cases during the first season, followed by explosive amplification and an epidemic during the second season, and then subsidence to maintenance levels.…”

Using geographic information systems and spatial and space-time scan statistics for a population-based risk analysis of the 2002 equine West Nile epidemic in six contiguous regions of Texas

“…Mosquitoes become infected from the blood of a viremic bird and then, depending on the mosquito species, transmit the virus to non-reservoir birds, other vertebrate animals, and humans. An ongoing WNV epizootic has since progressed westward across the U.S., northward into Canada, and southward into the Caribbean, Mexico/Central America, and South America [ 6 - 10 ]. During this progressive epizootic, it has been documented that WNV also can be transmitted human-to-human via transplacental passage, organ transplantation, and transfusion of blood and related products [ 11 ], although these are considered minor routes.…”