California encephalitis virus

California encephalitis virus was discovered in Kern County, California, and causes encephalitis in humans. Encephalitis is an acute inflammation of the brain that can cause minor symptoms, such as headaches, to more severe symptoms such as seizures. Mosquitoes serve as its carrier and for this reason this virus is known as an arbovirus (arthropod-borne virus).

California encephalitis virus belongs to the Orthobunyavirus genus of viruses. The La Crosse virus from the same genus is also a common cause of encephalitis in the United States. Other viruses with similar disease symptoms but genetically unrelated include: Saint Louis encephalitis and West Nile virus.