Synonyms: West-Nile fever
An acute arboviral infection caused by a virus of the Flaviviridae family transmitted by an infected mosquito that is asymptomatic in the majority of cases but that can present in rare occasions with mild flulike symptoms such as low-grade fever arthralgia myalgia and/or rash or with neurologic manifestations including meningitis encephalitis with mental confusion or disorientation tremors and acute flaccid paralysis/poliomyelitis.
Data from Orphanet are used to provide information on a disease's name, synonym(s), and overview. Reference: Access aggregated data from Orphanet at Orphadata. Orphadata: Free access data from Orphanet. © INSERM 1999. Available on http://www.orphadata.org. Data version April 2026
Newly diagnosed with
West-Nile encephalitis?
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Advocacy Organizations
Encephalitis Society
Our vision A world without death and disability from encephalitis. Our mission Rebuilding futures around the world by saving lives, accelerating awareness and driving research.
Genetic Epilepsy Team Australia
Collaboration of research and care
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Clinical Trials
For a list of clinical trials in this disease area, please click here.