https://www.blv.admin.ch/blv/fr/home/tiere/tierseuchen/uebersicht-seuchen/alle-tierseuchen/leberegel-dikrozoeliose-fasziolose.html 2016 false Switzerland French Italian German humans dicrocoeliasis fascioliasis dicrocoelium dicrocoeliasis fascioliasis fasciola hepatica animals scientific and technical information