What is West Nile virus?
West Nile virus is believed to have first appeared in the United States in 1999. It falls into the family of viruses that cause yellow fever and dengue fever. The virus can infect humans, birds, horses and some other animals, and is spread mostly through mosquito bites. People usually start to show symptoms of the virus from three to 14 days after being infected.
What are the symptoms?
About 80 percent of people who contract West Nile will feel no symptoms. Others can develop West Nile fever, which causes body aches, nausea and vomiting, lasting from a few days to several weeks.
About one in every 150 people infected suffer the virus' most severe symptoms: a high fever, disorientation, tremors, muscle weakness and paralysis. These symptoms can last several weeks and cause irreversible neurological damage.
How do you avoid contracting it?
Avoid mosquito bites by wearing insect repellent, checking door and window screens for holes, and emptying standing water - which can become breeding spots for mosquitoes - in flower pots and pools.
SOURCE: CENTERS FOR DISEASE CONTROL; NATIONAL INSTITUTES OF HEALTH