Encephalitis Epidemics in Australia.
—Epidemics of severe human encephalitis are in progress in various parts of this continent. The evidence indicates that they are due to the Japanese B type of encephalitis virus; horses and dogs are likely reservoirs; a mosquito is the possible vector, and migratory birds may be the means of introduction into the country.There have been previous epidemics of encephalitis in Australia—1917-1918, 1922, and 1925. The present epidemic showed itself early this year in an area known as the Murray Valley, in North Victoria. This area is used for irrigated agriculture, and mosquitoes are prevalent due to the abundant water.The typical case history is one of commencing irritability and headache, followed by nausea and vomiting with temperature to about 105 F. A moderate degree of neck stiffness then develops, with some irrationality, even to violence. Tremors and localized spasticity are common. Coma then develops, associated