title: The length of BTV-8 viraemia in cattle according to infection doses and diagnostic techniques.
abstract: Four groups of BTV free Frisian and cross bred calves were used to determine the length of viraemia following infection with different doses of BTV-8 Italian isolate. The first group of five animals was infected with 10 TCID(50) of BTV-8, the second group of four animals with 10(3) TCID(50) and the third group, which also included four animals, was infected with 10(6) TCID(50). A placebo containing uninfected tissue culture medium was given to the four animals of the fourth group. The viraemia was evaluated by real time RT-PCR and virus isolation. In all infected groups, virus isolation was able to detect infectious virus up to 39 days post infection (dpi) while RT-PCR was positive up to 151-157dpi. Infectious dose did influence neither the length nor the pattern of BTV-8 viraemia and confirmed that real time RT-PCR remains positive although no circulating virus is detectable in the peripheral circulation.
authors.affiliation: Istituto G. Caporale Teramo, Via Campo Boario, 64100 Teramo, Italy.
authors.forename: L
authors.initials: L
authors.lastname: Di Gialleonardo
authors.forename: P
authors.initials: P
authors.lastname: Migliaccio
authors.forename: L
authors.initials: L
authors.lastname: Teodori
authors.forename: G
authors.initials: G
authors.lastname: Savini
mesh_terms: D000818:Animals; D001819:Bluetongue / Q000821:virology*; D001820:Bluetongue virus / Q000235:genetics / Q000302:isolation & purification*; D002417:Cattle; D002418:Cattle Diseases / Q000821:virology*; D004305:Dose-Response Relationship, Drug; D007558:Italy; D012367:RNA, Viral / Q000235:genetics / Q000302:isolation & purification; D060888:Real-Time Polymerase Chain Reaction / Q000379:methods* / Q000662:veterinary; D020133:Reverse Transcriptase Polymerase Chain Reaction / Q000379:methods* / Q000662:veterinary; D013997:Time Factors; D014766:Viremia / Q000662:veterinary* / Q000821:virology
chemical_list: D012367:RNA, Viral