Abstracts
The Spread and Severity of the West Nile Virus in Ontario 2000-2004: Implications for Adaptation to Climate Change
Adam Fenech1, Don MacIver, and Heather Auld
1Environment Canada
adam.fenech@ec.gc.ca
The West Nile virus is a member of the Japanese encephalitis virus that can be spread to humans from birds through mosquito transmission. There have been infrequent human outbreaks, but more since the mid-1990s including the first outbreak in North America in New York City in 1999. The West Nile virus can cause death to humans through the onset of an encephalic fever (i.e. swelling of the brain tissue). This study traces the spread of the West Nile virus across Ontario over the past 5 summers, and associates climate variables to its spread and severity. A Geographic Information System (GIS) is used to show the spread and severity of the West Nile virus across Ontario from 2000 to 2004 on a common set of presentation maps. The study hypothesizes that the West Nile virus would be exacerbated by warmer winters allowing infected mosquitoes to survive the winter or migrating birds to winter in Ontario; by spring or early summer warmth to support bird migrations from West Nile virus infected areas of North America; and by summer heat to allow for the incubation and transmission of the West Nile virus through the bird-mosquito-human eco-chain. The study concludes that climate is but one of the many important variables affecting the spread and severity of the West Nile virus throughout Southern Ontario. As the virus has been shown to propagate in temperatures above 30 degrees Celsius, the study recommends the investigation of a climate indicator such as a "West Nile Virus Infection Threshold Alert" that could provide early warnings to the public to the increased threat of West Nile virus transmission due to higher temperatures.
2005-04-05 |
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