[1] CSIRO Livestock Ind, Australian Anim Hlth Lab, Geelong, Vic 3220, Australia
[2] Minist Agr & Forestry, Dept Livestock & Fisheries, Lao Pdr, Australia
[3] AFRC, Inst Anim Hlth, Pirbright Lab, Woking GU24 0NF, Surrey, England
[4] Swedish Univ Agr Sci, Dept Clin Sci, SE-75007 Uppsala, Sweden
[5] Mahidol Univ, Fac Trop Med, Mahidol Oxford Trop Med Res Unit, Bangkok 10400, Thailand
[6] John Radcliffe Hosp, Nuffield Dept Clin Med, Ctr Trop Med, Oxford OX3 9DU, England