we also have west nile, but for a number or reasons aren't as badly affected by it (although there are a few deaths every year among the very old or immune deficient)...
for one thing, it's been around here for years and years, so the population has been exposed to it....the claims are that over time people build up immunity...
also, right now it's the dry seaon (no rain at all....not even one little drop for at least 6 months), not exactly conducive to mosquitos....once it starts raining, the little buggers will have a place to grow (standing water)....
but take my word for it, we have a lot more threatening things to worry about than a few mosquitos.......we'd be lucky if that was the worst of our problems...