Animals Involved
Swine, wild birds are important maintenance hosts; horses ill but epidemiologically unimportant in amplification; other mammals, reptiles, amphibians may be infected, usually asymptomatically
Known Distributions
Asia, Australia, Papua New Guinea, Pacific islands from Japan to the Philippines
Probable Means of Spreading
Mosquito bites (Culex tritaeniorhynchus) important in maintenance cycle, other Culex and Aedes spp can transmit); also through broken skin or mucous membranes after direct contact with infected tissues
Clinical Manifestations in People
Fever, chills, myalgia, severe headache, GI symptoms; can progress to severe encephalitis; neurologic sequelae very common in survivors of encephalitis; case fatality rate 15%–30%