1. Department of Veterinary Microbiology and Parasitology; Faculty of Veterinary Medicine; University College Dublin; Belfield Dublin 4 Ireland
2. Department of Statistics; University College Dublin; Belfield Dublin 4 Ireland
3. Pig Production Department; Moorepark Research Centre; Teagasc, Fermoy County Cork Ireland
4. Central Veterinary Research Laboratory; Abbotstown, Castleknock Dublin 15 Ireland