There is great information out there and all you need to do is do a simple search and get the info you need. You can visit your state, county, town, or city websites, health dept websites, etc to see if you need to know what is going on in your area, also they will give you some prevent tips everyone could use to simply to keep the pesky little buggers at bay!
Here is a copy and pasted information from the CDC on the subject, as I do not have proficiency in west nile virus and the like. Here is there link if you want to visit there website. They have all this information in a PDF form for easy printing and saving needs for you!
What Is West Nile Virus?
West Nile virus (WNV) is a potentially serious illness. Experts believe WNV is established as a seasonal epidemic in North America that flares up in the summer and continues into the fall. This fact sheet contains important information that can help you recognize and prevent West Nile virus.
What Can I Do to Prevent WNV?
New! Prevention measures consist of community-based mosquito control programs that are able to reduce vector populations, personal protection measures to reduce the likelihood of being bitten by infected mosquitoes, and the underlying surveillance programs that characterize spatial/temporal patterns in risk that allow health and vector control agencies to target their interventions and resources.
The easiest and best way to avoid WNV is to prevent mosquito bites.
- When you are outdoors, use insect repellent containing an EPA-registered active ingredient. Follow the directions on the package.
- Many mosquitoes are most active at dusk and dawn. Be sure to use insect repellent and wear long sleeves and pants at these times or consider staying indoors during these hours.
- Make sure you have good screens on your windows and doors to keep mosquitoes out.
- Get rid of mosquito breeding sites by emptying standing water from flower pots, buckets and barrels. Change the water in pet dishes and replace the water in bird baths weekly. Drill holes in tire swings so water drains out. Keep children's wading pools empty and on their sides when they aren't being used.
There is more great info on the site, signs, symptoms, etc.