ABSTRACT
Small groups of bulls were exposed to natural infection with arboviruses. The bulls were bled and ejaculated regularly and the blood and semen were processed for virus isolation. Over a 5-year observation period, virus isolation and serology indicated that the 29 exposed bulls had experienced 79 viraemic episodes with the viruses of the bluetongue, epizootic haemorrhagic disease, Palyam and Simbu serogroups and an incompletely characterised rhabdovirus. In no instance was there unequivocal evidence of bluetongue virus contamination of semen, despite 18 infections in the study period.
Subject(s)
Arboviruses/isolation & purification , Blood/microbiology , Bluetongue virus/isolation & purification , Cattle Diseases/microbiology , Reoviridae/isolation & purification , Semen/microbiology , Animals , Antibodies, Viral/analysis , Arbovirus Infections/blood , Arbovirus Infections/microbiology , Arbovirus Infections/veterinary , Bluetongue/microbiology , Cattle , Cattle Diseases/diagnosis , Male , Serologic Tests , Sheep/microbiologyABSTRACT
Over 700 arboviruses were recovered between 1981 and 1987 from the blood of sentinel livestock near Darwin. Twenty-three isolates were made from sheep, goats, swamp buffalo (Bubalus bubalis) and horses, and the remainder were from cattle. The isolates have been typed as 27 separate viruses belonging to the bluetongue, epizootic haemorrhagic disease, Palyam, Simbu, bovine ephemeral fever, Tibrogargan and alphavirus groups. Ten of these viruses have not been isolated elsewhere in Australia and four have been isolated only in Darwin. Considerable annual variations in virus activity and in the durations of detectable viraemia were observed.
