West Nile encephalitis

encephalitis /en·ceph·a·li·tis/ (en-sef″ah-li´tis) pl. encephali´tides   Inflammation of the brain.

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acute disseminated encephalitis  see under encephalomyelitis.

equine encephalitis  see under encephalomyelitis.

hemorrhagic encephalitis  that in which there is inflammation of the brain with hemorrhagic foci and perivascular exudate.

herpes encephalitis  that caused by herpesvirus, characterized by hemorrhagic necrosis of parts of the temporal and frontal lobes.

HIV encephalitis  see under encephalopathy.

Japanese B encephalitis  a form of epidemic encephalitis of varying severity, caused by a flavivirus and transmitted by the bites of infected mosquitoes in eastern and southern Asia and nearby islands.

La Crosse encephalitis  that caused by the La Crosse virus, transmitted by Aedes triseriatus and occurring primarily in children.

lead encephalitis  see under encephalopathy.

postinfectious encephalitis , postvaccinal encephalitis acute disseminated encephalomyelitis.

St. Louis encephalitis  a viral disease first observed in Illinois in 1932, closely resembling western equine encephalomyelitis clinically; it is usually transmitted by mosquitoes.

tick-borne encephalitis  a form of epidemic encephalitis usually spread by the bites of ticks infected with flaviviruses, sometimes accompanied by degenerative changes in other organs.

West Nile encephalitis  a usually mild, febrile form caused by the flavivirus West Nile virus, transmitted by Culex mosquitoes and first observed in Uganda; symptoms may include drowsiness, severe frontal headache, maculopapular rash, abdominal pain, loss of appetite, nausea, and generalized lymphadenopathy.

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West Nile encephalitis

[west nīl]

Etymology: West Nile River valley and region in northern Uganda, where the disease was first observed in 1937

a mild, febrile, sporadic disease caused by the West Nile virus, transmitted by Culex mosquitoes and occurring chiefly in the summer; infection often does not lead to encephalitis. It may be of sudden onset, and symptoms may include drowsiness, severe frontal headache, maculopapular rash, abdominal pain, loss of appetite, nausea, and generalized lymphadenopathy. Most people infected with West Nile encephalitis are asymptomatic or experience flulike symptoms. Care is supportive. Many recover quickly but may experience prolonged malaise. Also called West Nile fever.