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Definition
By Mayo Clinic staffWest Nile infection is caused by a virus transmitted by mosquitoes. Most people infected with West Nile virus don't experience any signs or symptoms, or may experience only minor ones, such as fever and mild headache. However, some people who become infected with West Nile virus develop a life-threatening illness that includes inflammation of the brain.
Mild signs and symptoms of a West Nile virus infection generally go away on their own. But severe signs and symptoms — such as a severe headache, fever, disorientation or sudden weakness — require immediate attention.
Exposure to mosquitoes where West Nile virus exists increases your risk of getting West Nile virus infection. Protect yourself from mosquitoes by using mosquito repellent and wearing clothing that covers your skin to reduce your risk.
- West Nile virus: Questions and answers. Centers for Disease Control and Prevention. http://www.cdc.gov/ncidod/dvbid/westnile/qa/symptoms.htm. Accessed Sept. 5, 2012.
- West Nile virus: Fact sheet. Centers for Disease Control and Prevention. http://www.cdc.gov/ncidod/dvbid/westnile/wnv_factSheet.htm. Accessed Sept. 5, 2012.
- Petersen LR. Clinical manifestations and diagnosis of West Nile virus infection. http://www.uptodate.com/ index. Accessed Sept. 5, 2012.
- Ferri FF. Ferri's Clinical Advisor 2013: 5 Books in 1. Philadelphia, Pa.: Mosby Elsevier; 2012. http://www.mdconsult.com/books/about.do?eid=4-u1.0-B978-0-323-08373-7..00002-9&isbn=978-0-323-08373-7&about=true&uniqId=343863096-23. Accessed Sept. 6, 2012.
- West Nile virus. National Institute of Allergy and Infectious Diseases. http://www.niaid.nih.gov/topics/westnile/understanding/pages/what.aspx. Sept. 6, 2012.
- Centers for Disease Control and Prevention, et al. West Nile virus and other arborviral diseases — United States, 2011. MMWR. 2012;61:510. http://www.cdc.gov/mmwr/preview/mmwrhtml/mm6127a3.htm?s_cid=mm6127a3_w. Accessed Sept. 5, 2012.
- Petersen LR. Treatment and prevention of West Nile virus infection. http://www.uptodate.com/ index. Accessed Sept. 5, 2012.
- Updated information regarding insect repellants. Centers for Disease Control and Prevention. http://www.cdc.gov/ncidod/dvbid/westnile/RepellentUpdates.htm. Accessed Sept. 7, 2012.
- Anderson CF (expert opinion). Mayo Clinic, Rochester, Minn. Sept. 10, 2012.
- Mahoney KR (expert opinion). Food and Drug Administration, Rockville, Md. Jan. 10, 2011.
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