title: Excretion of transmissible spongiform encephalopathy infectivity in urine.
abstract: The route of transmission of most naturally acquired transmissible spongiform encephalopathy (TSE) infections remains speculative. To investigate urine as a potential source of TSE exposure, we used a sensitive method for detection and quantitation of TSE infectivity. Pooled urine collected from 22 hamsters showing clinical signs of 263K scrapie contained 3.8 +/- 0.9 infectious doses/mL of infectivity. Titration of homogenates of kidneys and urinary bladders from the same animals gave concentrations 20,000-fold greater. Histologic and immunohistochemical examination of these same tissues showed no indications of inflammatory or other pathologic changes except for occasional deposits of disease-associated prion protein in kidneys. Although the source of TSE infectivity in urine remains unresolved, these results establish that TSE infectivity is excreted in urine and may thereby play a role in the horizontal transmission of natural TSEs. The results also indicate potential risk for TSE transmission from human urine-derived hormones and other medicines.
authors.affiliation: Veterans Affairs Medical Center, Baltimore, Maryland 21201, USA.
authors.forename: Luisa
authors.initials: L
authors.lastname: Gregori
authors.forename: Gabor G
authors.initials: GG
authors.lastname: Kovacs
authors.forename: Irina
authors.initials: I
authors.lastname: Alexeeva
authors.forename: Herbert
authors.initials: H
authors.lastname: Budka
authors.forename: Robert G
authors.initials: RG
authors.lastname: Rohwer