Sera of healthy blood donors living in Switzerland were used to define a cut-off for distinguishing between positive and negative test results. In ELISA, 50 blood donor sera were used. In microarray, a single serum and 2 pools made of 5 sera each were used. For testing diagnostic peptide reactivity in ELISA, 44 sera from E. multilocularisand 35 sera from E. granulosus-infected patients from Central Europe were used. All echinococcosis patients had active hepatic lesions of either CE1 or CE2 type (WHO-IWGE standardized classification) and all sera were sampled prior to any therapeutic intervention, i.e. before surgery and/or chemotherapy. Diagnoses were confirmed serologically as described by Müller et al. [26] , in complementation to the clinical diagnosis based on imaging procedures and, if available, retrospective histopathological investigations. For testing cross-reactivity of the peptides, sera from patients with following infections were used (concomitant echinococcosis was ruled out by clinical and serological criteria): 2 trichinellosis, 2 trichuriasis, 10 toxocariasis, 8 ascariasis, 1 anisakiasis, 2 hookworm infection, 8 strongyloidiasis, 10 filariasis (Loa loa, Mansonella perstans, Onchocerca volvulus), 10 fascioliasis, 1 paragonimiasis, 11 schistosomiasis (Schistosoma mansoni, S. haematobium, S. mekongi), 12 neurocysticercosis