The Generative Brain

USDA ARS National Animal Disease Center (Ames, Iowa)

The National Animal Disease Center (NADC) in Ames, Iowa is a federal laboratory of the US Department of Agriculture's Agricultural Research Service. Its Virus and Prion Research Unit studies livestock viruses and prions, with a stated goal of methods to diagnose, control and inactivate prion diseases. For prion disease it matters mainly as the US public lab that runs long cross-species transmission studies in large animals: sheep scrapie, CWD and BSE in cattle, deer, sheep and pigs. It confirmed the first US BSE case in 2003 and described the 2008 H-type BSE case in a cow carrying E211K, the bovine counterpart of the human E200K mutation. Its scientists co-authored the 2015 study in which sheep scrapie transmitted to a macaque, and they contribute animal prion material and RT-QuIC methods to human and wildlife diagnostic work. Information only, not medical or veterinary advice.

Key facts

  • NADC sits in the ARS Midwest Area at 1920 Dayton Avenue, Ames; its Virus and Prion Research Unit has the mission of identifying and characterising viruses, bacteria and prions in economically important livestock diseases, including methods to diagnose, control and inactivate prion diseases.
  • In 2004 ARS described itself as the only organisation studying all four animal TSEs (BSE, scrapie, CWD and transmissible mink encephalopathy), with NADC holding large-animal biocontainment suited to incubation periods of up to a decade.
  • NADC confirmed the first US BSE case by western blot about 22 hours after samples arrived on 24 December 2003; the cow was later traced to Canadian origin.
  • An NADC study published in 1994 transmitted US sheep scrapie to calves by intracerebral inoculation, with disease after 14 to 18 months that did not look like BSE; ARS later reported that oral dosing of cattle with scrapie produced no detectable disease.
  • An NADC study of 13 calves inoculated intracerebrally with mule deer CWD found abnormal prion protein in five (38 percent) after six years, with subtle or absent lesions, and judged natural oral spread to cattle would need far larger doses if it occurs.
  • In 2007 NADC characterised two US BSE cases, one with typical features and one with an unusual prion protein pattern and no clear spongiform change.
  • An NADC scientist and an APHIS laboratory colleague reported in 2008 an H-type (atypical) BSE case in an Alabama beef cow carrying a new E211K variant, matching the human E200K mutation; the variant was not found in over 8,000 other US cattle, an estimated frequency below 1 in 2,000.
  • In 2023 the unit reported that cattle with one or two copies of K211 developed H-type BSE significantly faster than EE211 cattle after intracranial inoculation.
  • With external co-authors, NADC led work that produced cattle lacking prion protein by gene targeting (published 2007); they were healthy at over 20 months and their brain tissue resisted prion propagation in vitro.
  • Two NADC scientists co-authored Comoy 2015, in which a natural classical scrapie isolate transmitted to a cynomolgus macaque after about 10 years and produced disease resembling sporadic CJD.
  • An NADC scientist co-authored the 2025 mBio study finding that pigs challenged with BSE carried more seeding-competent prions than pigs given CWD or scrapie, and that BSE pig tissue could misfold human prion protein in vitro.
  • An NADC scientist is a co-author on the 2024 large validation of skin RT-QuIC in human prion disease led by Case Western Reserve University.
  • Recent unit methods work includes RT-QuIC on fixed paraffin-embedded tissue without organic solvents (2024) and a multi-agency validation of RT-QuIC on rectal biopsies from pre-clinical white-tailed deer, peak sensitivity 76.8 percent.
  • A literature index search finds prion papers with NADC affiliation from the 1990s to 2026, including the third-eyelid scrapie test and studies of sheep scrapie in white-tailed deer.
  • A 2025 fellowship posting, seen only as a search excerpt, says the prion programme now also covers emerging camel prion disease.

Timeline

  1. 1994NADC reports intracerebral transmission of sheep scrapie to cattle.
  2. 2003NADC confirms the first US BSE case within about 22 hours of receiving samples.
  3. 2004ARS magazine describes NADC TSE work on scrapie, BSE and CWD.
  4. 2005NADC reports intracerebral transmission of mule deer CWD to cattle.
  5. 2006Prion-protein-free cattle produced with NADC as lead institution are e-published.
  6. 2007NADC characterises two US BSE cases.
  7. 2008Report of the H-type BSE case with the E211K variant.
  8. 2015Comoy et al., with NADC co-authors, report scrapie transmission to a macaque.
  9. 2023H-type BSE incubation shown to be shorter in EK211 and KK211 cattle.
  10. 2024Skin RT-QuIC validation in human prion disease published with an NADC co-author.
  11. 2024Deer rectal mucosa RT-QuIC validation published.
  12. 2025Pig BSE, scrapie and CWD study published in mBio.
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