A viral disease of eastern and southern Africa, originally recognized in livestock and later found also to affect humans, caused by a phlebovirus, transmitted by mosquitoes, and characterized by severe disease with hepatitis, enteritis, and abortion in livestock and (usually) a milder acute febrile illness in humans.
Origin
1930s.
Definition of Rift Valley fever in US English:
Rift Valley fever
noun
A viral disease of eastern and southern Africa, originally recognized in livestock and later found also to affect humans, caused by a phlebovirus, transmitted by mosquitoes, and characterized by severe disease with hepatitis, enteritis, and abortion in livestock and (usually) a milder acute febrile illness in humans.