About the Authors
Institute for Animal Health, Pirbright Laboratory, Pirbright, Woking, Surrey, United Kingdom
Division of Environmental and Evolutionary Biology, University of Glasgow, Glasgow, United Kingdom
Animal Health and Welfare, Defra, London, United Kingdom
The authors have declared that no competing interests exist.
Conceived and designed the experiments: EC DK DP NK. Performed the experiments: EC JW AS RR LG SM NM PM KE YL ER NJ NF. Analyzed the data: EC JWW DH DK DP NK. Contributed reagents/materials/analysis tools: EC YL ER NJ NF DH NK. Wrote the paper: EC DH DK DP NK.