Unspecified Encephalitis

Unspecified Encephalitis, also known as primary encephalitis, is a swelling of the brain caused by viral infections transmitted by animals such as mosquitos, ticks, and horses. The most commonly known type of enchephalitis in the United States is the West Nile Virus, which was transmitted by mosquitoes who had previously fed on infected birds. Mild symptoms include fever, lethargy, and irritability; severe sypmtoms can include convulsions, comas, delirium, and death.