[1] Cent Sci Lab, York YO41 1LZ, N Yorkshire, England
[2] Univ Edinburgh, Ctr Trop Vet Med, Roslin EH25 9RG, Midlothian, Scotland
[3] Univ Salford, Cestode Zoonoses Res Grp, Biosci Res Inst, Salford M5 4WT, Lancs, England
[4] Univ Salford, Ctr Mol Epidemiol & Ecol, Salford M5 4WT, Lancs, England
[5] Univ Hohenheim, Inst Zool Parasitol, D-70599 Stuttgart, Germany
[6] Univ Ulm, Sect Infect & Clin Immunol, D-89081 Ulm, Germany