Epidemiological Characteristics of Classical Scrapie Outbreaks in 30 Sheep Flocks in the United Kingdom
2008

Epidemiological Characteristics of Classical Scrapie Outbreaks in UK Sheep Flocks

Sample size: 30 publication 15 minutes Evidence: moderate

Author Information

Author(s): K. Marie McIntyre, Simon Gubbins, Wilfred Goldmann, Nora Hunter, Matthew Baylis

Primary Institution: Pirbright Laboratory, Institute for Animal Health

Hypothesis

What are the epidemiological characteristics of sheep flocks naturally infected with classical scrapie?

Conclusion

The study found significant variation in the epidemiological characteristics of scrapie outbreaks among different sheep flocks, influenced by flock-level prion protein genotype profiles.

Supporting Evidence

  • The study involved PrP genotype data for nearly 8600 animals and over 400 scrapie cases.
  • Most scrapie cases were found in just two PrP genotypes: ARQ/VRQ and VRQ/VRQ.
  • The age-at-onset of clinical signs varied significantly among flocks and genotypes.
  • Evidence suggested that purchasing infected animals is a key way scrapie is introduced to flocks.
  • Seasonality in cases was associated with lambing time in certain flocks.

Takeaway

This study looked at how scrapie affects different sheep flocks and found that the type of sheep and their genetics can change how the disease spreads.

Methodology

The study analyzed PrP genotype data from nearly 8600 animals and over 400 scrapie cases across 30 sheep flocks.

Potential Biases

There may be bias in reporting as farmers might have become more adept at identifying scrapie during outbreaks.

Limitations

The study's design may have truncated outbreak durations as farmers received genotype information, potentially affecting the observed epidemiological characteristics.

Participant Demographics

The study involved 30 sheep flocks across the UK, varying in breed and size.

Statistical Information

P-Value

p<0.001

Statistical Significance

p<0.05

Digital Object Identifier (DOI)

10.1371/journal.pone.0003994

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