Veterinary Parasitology 110 (2002) 57–76 Evaluation of three enzyme-linked immunosorbent assays (ELISAs) for the detection of serum antibodies in sheep infected with Echinococcus granulosus Reinhold Kittelberger a,∗ , Michael P. Reichel b , Judy Jenner a , David D. Heath c , Marshall W. Lightowlers d , Pedro Moro e , Mohamed M. Ibrahem f , Philip S. Craig f , Joseph S. O’Keefe a a National Centre for Disease Investigation, Ministry of Agriculture and Forestry, P.O. Box 40742, Ward Street, Upper Hutt, New Zealand b Novartis Animal Health Australasia Pty Ltd., 245 Western Road, Kemps Creek, NSW 2171, Australia c AgResearch, Wallaceville Animal Research Centre, Ward Street, Upper Hutt, New Zealand d University of Melbourne, Veterinary Clinical Centre, Princess Highway, Werribee, Vic. 3030, Australia e Department of Pathology, Universidad Peruana Cayetano Heredia, P.O. Box 5045, Lima, Peru f Cestode Zoonoses Research Group, Biosciences Research Institute, University of Salford, Salford M5 4WT, UK Received 11 April 2002; received in revised form 25 July 2002; accepted 8 August 2002 Abstract The aim of this study was to develop an immunological method for the identification of sheep infected with Echinococcus granulosus which would allow the monitoring of animals imported into countries free from hydatidosis and as an aid to countries where control schemes for the disease are in operation. Three enzyme-linked immunosorbent assays (ELISAs) were developed and validated, using as antigen either a purified 8 kDa hydatid cyst fluid protein (8kDaELISA), a recombinant EG95 oncosphere protein (OncELISA) or a crude protoscolex preparation (ProtELISA). Sera used for the assay validations were obtained from 249 sheep infected either naturally or experimentally with E. granulosus and from 1012 non-infected sheep. The highest diagnostic sensitivity was obtained using the ProtELISA at 62.7 and 51.4%, depending on the cut-off. Assay sensitivities were lower for the 8kDaELISA and the OncELISA. Diagnostic specificities were high, ranging from 95.8 to 99.5%, depending on the ELISA type and cut-off level chosen. A few sera from 39 sheep infected with T. hydatigena and from 19 sheep infected with T. ovis were recorded as positive. Western immunoblot analysis revealed that the dominant antigenic components in the ∗ Corresponding author. Tel.: +64-4-526-5629; fax: +64-4-526-5601. E-mail address: kittelbergerr@maf.govt.nz (R. Kittelberger). 0304-4017/02/$ – see front matter © 2002 Published by Elsevier Science B.V. PII:S0304-4017(02)00308-4