title: Prion diseases are efficiently transmitted by blood transfusion in sheep.
abstract: The emergence of variant Creutzfeld-Jakob disease, following on from the bovine spongiform encephalopathy (BSE) epidemic, led to concerns about the potential risk of iatrogenic transmission of disease by blood transfusion and the introduction of costly control measures to protect blood supplies. We previously reported preliminary data demonstrating the transmission of BSE and natural scrapie by blood transfusion in sheep. The final results of this experiment, reported here, give unexpectedly high transmission rates by transfusion of 36% for BSE and 43% for scrapie. A proportion of BSE-infected transfusion recipients (3 of 8) survived for up to 7 years without showing clinical signs of disease. The majority of transmissions resulted from blood collected from donors at more than 50% of the estimated incubation period. The high transmission rates and relatively short and consistent incubation periods in clinically positive recipients suggest that infectivity titers in blood were substantial and/or that blood transfusion is an efficient method of transmission. This experiment has established the value of using sheep as a model for studying transmission of variant Creutzfeld-Jakob disease by blood products in humans.
authors.affiliation: Neuropathogenesis Division, Roslin Institute, Compton, United Kingdom. f.houston@vet.gla.ac.uk
authors.forename: Fiona
authors.initials: F
authors.lastname: Houston
authors.forename: Sandra
authors.initials: S
authors.lastname: McCutcheon
authors.forename: Wilfred
authors.initials: W
authors.lastname: Goldmann
authors.forename: Angela
authors.initials: A
authors.lastname: Chong
authors.forename: James
authors.initials: J
authors.lastname: Foster
authors.forename: Silvia
authors.initials: S
authors.lastname: Sisó
authors.forename: Lorenzo
authors.initials: L
authors.lastname: González
authors.forename: Martin
authors.initials: M
authors.lastname: Jeffrey
authors.forename: Nora
authors.initials: N
authors.lastname: Hunter
mesh_terms: D000465:Algorithms; D000818:Animals; D001782:Blood Donors; D001803:Blood Transfusion / Q000662:veterinary; D002417:Cattle; D018450:Disease Progression; D004526:Efficiency; D016643:Encephalopathy, Bovine Spongiform / Q000097:blood / Q000235:genetics / Q000473:pathology / Q000635:transmission; D020022:Genetic Predisposition to Disease; D017096:Prion Diseases / Q000097:blood / Q000473:pathology / Q000635:transmission* / Q000662:veterinary; D012608:Scrapie / Q000097:blood / Q000235:genetics / Q000473:pathology / Q000635:transmission; D012756:Sheep; D013997:Time Factors; D065227:Transfusion Reaction