Equine Encephalomyelitis: Causative Arboviruses

Virus Species or Variant

Geographic Location

Most Important Reservoir

Alphaviruses

EEEV

Eastern North America, primarily east of Mississippi River

Birds

Madariaga virus

South America, Caribbean

Rodents

Western equine encephalitis virus

Western North America, Central and South America

Birds, rabbits, and snakes

Highlands J virus

Eastern North America (as for EEEV)

Birds

Venezuelan equine encephalitis virus

Central and South America, Caribbean

Cotton rat and other rodents

Everglades virus

South Florida (US)

Rodents

Ross River virus

Australia, Papua New Guinea

Marsupial and placental mammals

Semliki Forest virus

East and West Africa

Unknown

Una virus

South America

Birds

Flaviviruses

Japanese encephalitis

Asia: particularly India and Russia; Western Pacific

Birds, swine

Murray Valley

Australia, Papua New Guinea

Birds, marsupials, and foxes

Kunjin virus

Australia

Birds (herons and ibis)

St. Louis encephalitis

North, Central, and South America

Birds

Usutu virus

Europe, Africa

Birds

West Nile virus

Africa; Middle East; Europe; North, Central, and South America; Australia

Passerine birds

Louping ill virus

Iberian Peninsula, UK

Sheep, grouse

Powassan virus

North America, Russia

Lagomorphs, rodents, mice, skunks

Tickborne encephalitis

Asia, Europe: particularly Finland and Russia

Small rodents

EEEV, eastern equine encephalitis virus.