Peaton virus: a new Simbu group arbovirus isolated from cattle and Culicoides brevitarsis in Australia.

A new member of the Simbu group of arboviruses, for which the name Peaton virus is proposed, has been isolated from midges and cattle in Australia. Nine isolates were obtained from 101 pools of the biting midge Culicoides brevitarsis collected at Peachester, Qld, (26·51 oS., 152·53 °E.) between 30 November and 8 December 1976. Three isolations of the same virus were made from the blood of sentinel cattle collected at Grafton and Tamworth, N.S.W., on 20 January and 13 April 1977, respectively. Peaton virus was shown to be a member of the Simbu group of arboviruses by complement- fixation tests using antisera prepared against Australian strains of Akabane and Aino viruses. It was readily distinguishable from these viruses in cross-neutralization tests in tissue cultures and mice. A serological survey of sentinel cattle showed that neutralizing antibody was detectable only in cattle within the recorded limits of the suspected vector C. brevifarsis. Neutralizing antibody in blood serum was detected in 22 of 157 sheep, 21 of 137 horses, 7 of 18 buffaloes, 7 of 20 goats and 3 of 62 pigs, but not in 22 camels, 34 dogs, 3 cats, 76 human beings, 240 marsupials, 19 reptiles or 31 wild birds. The pathogenicity of Peaton virus has yet to be determined. The Yale Arbovirus Research Unit and the Center for Disease Control, Fort Collins, U.S.A., found that Peaton virus was distinguishable from all other Simbu group viruses and thus is a new virus.