tropics head north

When you think of Canada you think of snow mountains skiing, and especially the cold. Would you be surprised If I said diseases that are connected with the topics are in Canada to stay.
Before 7 years ago they never heard of West Nile and now 800 people have died from it in Canada.
They say this is because the rise of floods and warmer winters. These 2 conditions are contributed to climate change.

http://www.washingtonpost.com/wp-dyn/content/article/2006/05/04/AR2006050401931.html