Douglas and Tinaroo Viruses: Two Simbu Group Arboviruses Infecting Culicoides brevitarsis and Livestock in Australia

Abstract

Two Australian members of the Simbu group, Douglas and Tinaroo viruses, were found to be distinct, by virus-neutralization tests, from three previously known Simbu group viruses isolated in Australia, namely Akabane, Aino and Peaton viruses. A low-titre, two-way, cross-reaction was noted between Akabane and Tinaroo viruses. Antibody to Tinaroo and Douglas viruses was detected in serum from cattle, buffalo, sheep, goats and deer but not in humans, pigs, kangaroos and wallabies. The results for horses were inconclusive. The distribution of antibodies to each virus falls mainly within the geographical distribution of the biting midge Culicoides brevitarsis, an insect from which each virus has been isolated.