Never ceases to amaze me how people just pass, what could and most likely will be, a devastating epidemic, off as just a low grade virus. When this thing first started a couple of years ago, we were told that there would hardly be any additional cases. Looks like we passed that stage a few months ago. Personally I am still not convinced that WNV wasn't deliberately introduced to the USA by a foreign source.
My wife is in medicine, she and her coworkers have thought the same thing!
As much as it pains me to say it, you are not the first or only person to entertain this thought. I must ask you then, "For what purpose?" To make a few people sick and even fewer, mostly old people, die? Sorry for the skepticism, but there are a million other things far more deadly that a 'foreign source' could introduce than WNV.
Why the devil would an enemy go to the trouble merely to introduce a disease that has so little effect?