Race B et al. 2009, Susceptibilities of nonhuman primates to chronic wasting disease (Emerg Infect Dis 15(9))

A September 2009 paper from Rocky Mountain Laboratories (NIAID) and partners testing whether chronic wasting disease (CWD), the prion disease of deer, elk and moose, can infect two primate species used as stand-ins for humans. Squirrel monkeys became ill after intracerebral exposure and a few were infected by mouth, while cynomolgus macaques showed no disease at about 70 months. The authors read this as consistent with a species barrier protecting humans, while stating that macaque transmission could not be ruled out.

Key facts

  • Citation verified: Race B, Meade-White KD, Miller MW, Barbian KD, Rubenstein R, LaFauci G and colleagues (17 authors, senior author Bruce Chesebro), Emerg Infect Dis 2009;15(9):1366-1376, doi 10.3201/eid1509.090253, PMID 19788803.
  • Authors came from Rocky Mountain Laboratories plus the Colorado Division of Wildlife, SUNY Downstate, the New York State Institute for Basic Research, the American Red Cross and the University of Wyoming; funding was the NIAID intramural programme.
  • Squirrel monkeys inoculated into the brain: 11 of 13 became ill at 33 to 53 months after infection (mean about 41 months), with spongiform brain change and abnormal prion protein; some also had abnormal prion protein in lymphoid tissue.
  • Squirrel monkeys exposed orally: 3 of 15 had abnormal prion protein in tissues; two of them, at 69 months, in brain, spleen and lymph nodes, and one only in lymphoid tissue.
  • Cynomolgus macaques given CWD material by brain or oral routes showed no clinical disease at 70 months; one culled at 48 months for aggression had no abnormal prion protein.
  • Transgenic mice expressing deer or human prion protein inoculated with tissue from infected monkeys did not develop disease in 600 to 700 days.
  • The authors concluded epidemiologic and laboratory data support a species barrier protecting humans, but said macaque infection could not be excluded because oral BSE took at least 5 years to cause disease in macaques.
  • The authors also warned that human CWD might present as a metabolic wasting disorder and go untested for prion disease.
  • The abstract says 7 of 8 CWD isolates caused disease, whereas the results count 11 of 13 ill animals; the text does not reconcile these figures.

Timeline

  1. 1967CWD first recognised in captive deer in Colorado, per the paper's introduction.
  2. 2005Marsh and colleagues report two squirrel monkeys ill after intracerebral CWD inoculation, the earlier finding this paper extends.
  3. 2009Paper published in Emerging Infectious Diseases 15(9), reporting up to 70 months of follow-up.

Last checked 1 November 2026

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