Sections View Full Chapter Figures Tables Videos Annotate Full Chapter Figures Tables Videos Supplementary Content +++ Key Features ++ Epidemics occur in summer–fall Most infected individuals are asymptomatic West Nile Fever develops in 20% and is characterized by Fever Headache Retro-orbital pain Nausea, vomiting Lymphadenopathy Maculopapular rash (20–50%) Meningitis or encephalitis develops is < 1% of infected patients, but 10% of these cases are fatal +++ Clinical Findings ++ Children usually manifest with West Nile fever; neuroinvasive disease, most likely limited to meningitis develops in < one-third Neurologic manifestations are most often those found with other meningoencephalitides, but some distinguishing features include Polio-like acute flaccid paralysis Movement disorders (parkinsonism, tremor, and myoclonus) Brainstem symptoms Polyneuropathy Optic neuritis Muscle weakness, facial palsy, and hyporeflexia are common +++ Diagnosis ++ Diagnosis is best made by detecting IgM antibody (enzyme immunoassay) to the virus in cerebrospinal fluid Polymerase chain reaction is a specific diagnostic tool, but is less sensitive than antibody detection Antibody rise in serum can also be used for diagnosis +++ Treatment ++ Supportive Your MyAccess profile is currently affiliated with '[InstitutionA]' and is in the process of switching affiliations to '[InstitutionB]'. Please click ‘Continue’ to continue the affiliation switch, otherwise click ‘Cancel’ to cancel signing in. Get Free Access Through Your Institution Learn how to see if your library subscribes to McGraw Hill Medical products. Subscribe: Institutional or Individual Sign In Username Error: Please enter User Name Password Error: Please enter Password Forgot Username? Forgot Password? Sign in via OpenAthens Sign in via Shibboleth