There Is No Safe Dose of Prions
2011

There Is No Safe Dose of Prions

Sample size: 4338 publication Evidence: high

Author Information

Author(s): Helen R. Fryer, Angela R. McLean

Primary Institution: The Institute for Emerging Infections, Oxford Martin School, Department of Zoology, Oxford University, Oxford, United Kingdom

Hypothesis

Is there evidence of a threshold dose of prions below which the probability of infection is zero?

Conclusion

The study concludes that there is no safe dose of prions, as infection is possible even at very low doses.

Supporting Evidence

  • Infection is possible at doses three orders of magnitude lower than the ID50.
  • The dose-response curve matches predictions from a model that assumes no threshold for infection.
  • Mean incubation periods decrease linearly with dose above the ID50 but are invariant below it.
  • Observed variability in incubation periods is greater than predicted by the model.

Takeaway

Even tiny amounts of prions can make you sick, so there's no such thing as a safe dose.

Methodology

The study analyzed data from 127 experiments involving 4338 mice inoculated with varying doses of prions and used mathematical modeling to assess infection probabilities.

Limitations

The study could not rule out the possibility of a threshold dose due to limited sample sizes at very low doses.

Participant Demographics

Mice of various breeds were used in the experiments.

Digital Object Identifier (DOI)

10.1371/journal.pone.0023664

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