go here http://www.cdc.gov/ncidod/dvbid/westnile/
To be honest, I didn't think human cases of West Nile was found up in Toronto yet. By the way it is one of the more trivial mosquito borne disease. No child or young healthy adult has succombed to West Nile and died from it. All the deaths were the elderly. Down here in Georgia we have the much more deadly Eastern Equine Encephalitis but more people worry about West Nile due to the media inattention to Eastern Equine! In fact, we have only had one to two deaths (in the elderly) from it but I have seen young healthy folks die from Eastern Equine for years!
By the way, many people have a self limited mild illness with West Nile virus. Your chances of getting seriously ill from West Nile is about as good as being hit by lightning according to the CDC.
PS.... most of the "West Nile Activity" on the maps are related to finding them in birds rather than humans. Although Georgia looks like a hot bed of West Nile activity, we have had only 1 or 2 serious human illness due to it in the last three years.