California encephalitis

California encephalitis,

arthropod-borne encephalitis or encephalomeningitis, induced by an arbovirus. Infection usually is caused by a mosquito bite. Epidemics occur mainly in the Midwest, on the eastern seaboard, and in Texas and Louisiana. The virus was first isolated in California. The infection generally follows one of two clinical courses. The mild form is characterized by headache, malaise, GI symptoms, and a fever that may reach 104° F. The more severe form may be marked by a sudden onset of fever, vomiting, headaches, lethargy, and signs of neurologic involvement such as loss of reflexes, disorientation, seizure, loss of consciousness, and flaccid paralysis. Recovery usually begins in 1 week. Mortality rate is very low, but a significant number of patients have neurologic sequelae for 1 year or more. Treatment usually involves administration of anticonvulsant and sedative medications. See also arbovirus, encephalitis.

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California encephalitis

an encephalitis of humans caused by the La Crosse virus isolated from mosquitoes in California. Occurs experimentally in small laboratory rodents when the virus is injected intracerebrally. Suspected of natural passage through wild and domestic mammals.

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California encephalitis

A viral infection by any of 4 California Bunyaviridae; most CE is by the LaCrosse virotype, which occurs in the summer in north central US; in endemic regions, CE causes 20% of acute childhood meningitides with a very low mortality rate; the infectious cycle is maintained in the mosquito vector, Aedes triseriatus Clinical Non-specific viral prodrome, followed by a 3-8 day meningismus with spontaneous resolution Prognosis Excellent; rare psychological residua