People over 50 or with a weakened immune system are at the highest risk of serious illness as only 20 percent of people infected with WNV will display symptoms. These include fever, headache, body aches and sometimes nausea or vomiting. These symptoms usually last a few days, however, some people become sick and debilitated for several weeks. Severe symptoms include high fever, headache, neck stiffness, muscle weakness and disorientation. These symptoms can last several weeks and neurological effects, such as paralysis, can be permanent. Key prevention actions recommended by the Public Health Department are: Drain standing water around your home or business; repair or install tight-fitting screens on windows and doors; avoid outdoor activities at dusk and dawn; use an approved insect repellent on exposed skin; and wear long sleeves, long pants and socks when outdoors.