- Tim Daly, Gwinnett County Extension Agent
They interfere with outdoor activities and can also be vectors for several diseases. Malaria, yellow fever and dengue fever are problems in other parts of the world. In our area, West Nile virus and encephalitis are troublesome although only a small number of individuals are affected each year. Mosquitoes cannot be totally eliminated from the property, but their populations can be reduced to where they are not as bothersome.