a town in South Africa where the causative agent for the fever was first isolated. Wesselsbron fever - a mosquito-borne disease of sheep and humans caused by the Wesselsbron disease virus. Synonym(s): Wesselsbron disease; Wesselsbron virusWesselsbron disease - Synonym(s): Wesselsbron feverWesselsbron virus - Synonym(s): Wesselsbron fever