The Safety Measures are Fairly Common SenseA news release from the South Central Public Health District explained West Nile Virus was found in mosquito samples east of Twin Falls. The health district says there have been no serious human illnesses across the region this summer that have been reported. The older you are, you’ll probably notice an infection more than younger family members, some of whom may not notice any symptoms at all. West Nile March Across a Continent in Short OrderThe virus first arrived in North America 35 years ago, and then made its way westward. You probably won't encounter many mosquitoes in the middle of the day, but before sunset, the insects are active.