West Nile Encephalitis: Symptoms & Signs

Medically Reviewed on 9/9/2020

West Nile encephalitis is a brain infection. It is not directly contagious from person to person.

Most cases of West Nile virus infection are mild and do not cause serious symptoms. Most infections in the U.S. occur in the early fall. In certain cases, inflammation of the brain (encephalitis) develops in infected people. When symptoms and signs do occur, these typically include

If severe illness with encephalitis is present, symptoms can include

Cause of West Nile encephalitis

An infection with the West Nile virus (WNV) causes West Nile encephalitis. The infection spreads from infected birds to humans through the bite of mosquitos.

Other west nile encephalitis symptoms and signs


Bowel regularity means a bowel movement every day. See Answer

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Jameson, J. Larry, et al. Harrison's Principles of Internal Medicine, 20th Ed. New York: McGraw-Hill Education, 2018.