Emergence of a virulent strain of West Nile virus causing fatal equine encephalitis in south-eastern Australia. In 2011 a large outbreak of encephalitis in horses occurred in south-eastern Australia that was caused by a new virus that is transmitted by mosquitoes and is related to West Nile virus, known to cause severe disease in humans and horses. This project will study this new virus and develop improved methods for diagnosis and control of this disease.