title: The possible role of two common three-host ticks, Rhipicephalus appendiculatus and Amblyomma hebraeum, in the transmission of bovine leukosis virus.
abstract: The possible role of Rhipicephalus appendiculatus and Amblyomma hebraeum in the mechanical and transstadial transmission of bovine leukosis virus (BLV) was investigated. BLV-free laboratory strains of R. appendiculatus and A. hebraeum nymphal ticks (n = 400) were fed on a BLV-infected and a negative control bovine. At various intervals after engorgement the ticks were homogenised and injected subcutaneously into BLV-negative sheep. Adult R. appendiculatus and A. hebraeum, which had fed as nymphs on the BLV-infected bovine, were then allowed to feed on BLV-negative sheep. A control sheep was also injected intravenously with blood from the infected bovine. Only the control sheep that received blood from the BLV-positive bovine seroconverted 9 months later. All the other surviving sheep remained serologically negative during the 13 months observation period. It is suggested that the nymphal stages of these ticks probably do not play a role in the transstadial transmission of BLV in southern Africa. The significance of these results is discussed.
authors.affiliation: Department of Herd Health and Reproduction, Faculty of Veterinary Science, Medical University of Southern Africa, Medunsa, South Africa.
authors.forename: S D
authors.initials: SD
authors.lastname: Morris
authors.forename: N R
authors.initials: NR
authors.lastname: Bryson
authors.forename: D T
authors.initials: DT
authors.lastname: de Waal
authors.forename: O
authors.initials: O
authors.lastname: Matthee
authors.forename: E R
authors.initials: ER
authors.lastname: du Preez
authors.forename: M
authors.initials: M
authors.lastname: van Vuuren
authors.forename: E S
authors.initials: ES
authors.lastname: Kadish
mesh_terms: D000818:Animals; D000914:Antibodies, Viral / Q000097:blood; D001096:Arachnid Vectors; D002417:Cattle; D016583:Enzootic Bovine Leukosis / Q000635:transmission*; D001909:Leukemia Virus, Bovine / Q000302:isolation & purification; D013987:Ticks
chemical_list: D000914:Antibodies, Viral