Preliminary characterization of D'Aguilar virus and three Palyam group viruses new to Australia.

Between 1974 and 1980, 424 viruses were isolated at the Long Pocket Laboratories of the Division of Animal Health, CSIRO, either from insects or from the blood of sentinel cattle, and of these, 165 cross-reacted with D'Aguilar virus (an Australian Palyam group virus) in a complement fixation test. Neutralization tests were used to classify these viruses into four serotypes with the isolates D'Aguilar B8112, CSIRO 11, CSIRO 58 and CSIRO 82 as the type strains. The latter three were new to Australia. Like other orbiviruses, these four serotypes were partially sensitive to treatment with either or chloroform. Neutralizing antibodies against D'Aguilar, CSIRO 11 and CSIRO 58 viruses were detected in sera from cattle, buffalo, deer and sheep but not in sera from humans, horses, pigs or marsupials. Antibodies against CSIRO 82 virus were detected in 85% of 26 buffalo, and 0.4% of 495 cattle sera tested. The antibody distribution in Australia for D'Aguilar, CSIRO 11 and CSIRO 58 viruses fell within the distribution limits of Culicoides brevitarsis, the insect from which these viruses were most commonly recovered. The antibody distribution for CSIRO 82 virus, which was isolated from a pool containing C. schultzei and C. peregrinus, fell within the much more restricted distribution limits of these species. None of these viruses has been associated with disease.