Japanese B encephalitis is a disease caused by the mosquito-borne encephalitis virus. Domestic pigs and wild birds–namely herons–are reservoirs of the virus, and transmission to humans can cause severe symptoms: fever, headache, malaise, neck rigidity, cachexia, hemiparesis, convulsions, and a higher than normal body temperature. Japanese encephalitis can also lead to mental retardation, which itself usually leads to coma. The disease is most common in Southeast Asia and the Far East, though it is not transmitted from person to person, meaning that patients do not need to be isolated.
There is no specific treatment for Japanese treatment, and treatment is largely supportive, though intracranial pressure can be relieved with mannitol. A Japanese encephalitis vaccine exists, and confers lifelong immunity.