Comparison of three immunodiagnostic tests for experimental Heterophyes heterophyes infection in dogs Attef M. Elshazly a , Hany M. Elsheikha b,c, * , Mohammad H. Rahbar d , Soha I. Awad a a Department of Parasitology, Faculty of Medicine, Mansoura University, Mansoura 35516, Egypt b Department of Parasitology, Faculty of Veterinary Medicine, Mansoura University, Mansoura 35516, Egypt c Division of Veterinary Medicine, The School of Veterinary Medicine and Science, The University of Nottingham, College Road, Sutton Bonington Campus, Leicestershire LE12 5RD, United Kingdom d Department of Epidemiology, College of Human Medicine, Michigan State University, East Lansing, MI 48824, USA Received 22 May 2007; received in revised form 25 October 2007; accepted 30 October 2007 Abstract The aim of this study was to compare the performance of three in-house diagnostic tests, i.e. counter current immunoelec- trophoresis (CCIE), intradermal (ID) and indirect fluorescent immunoassay (IFI), for the diagnosis of Heterophyes infection. One hundred and twenty puppies were randomly divided into eight groups (n = 15/group). Heterophyes heterophyes infections were established in these puppies by administering a dose of 50 H. heterophyes encysted metacercariae/puppy by gavage. Forty puppies of similar age and sex were divided into eight groups, of five puppies each and were used as negative controls. Sera pooled from separate infected and uninfected groups were tested against H. heterophyes antigens, weekly for 8 weeks post-infection (PI). The ID assay detected infected puppies sooner than any of the serological tests. Sero-conversion was first detected 2 weeks PI by ID assay and 1 week later by CCIE and IFI assays. ID test performed well till the end of the experiment (sensitivity and specificity: 100% and 90%, respectively). Both IFI and CCIE assays had a sensitivity of 40% and 20%, respectively for early detection of antibody, which was less sensitive than ID but both assays were more specific (100%) than the ID assay. The lowest agreement was between ID and IFI tests (40.3%), whilst the highest was observed between CCIE and IFI tests (67.2%). Of the three evaluated methods, the ID test could be recommended for scientific and laboratory diagnosis of heterophyosis in naturally infected animals. However, since none of the investigated method are optimal (i.e, offers 100% specificity and sensitivity), the choice of test employed must depend on the aim of the study. # 2007 Elsevier B.V. All rights reserved. Keywords: Heterophyosis; Dogs; Diagnosis; Serology; Experimental 1. Introduction The Heterophyidae (Trematoda: Digenea) have a three-host life cycle. As adults they live in a vertebrate definitive host (humans and other fish-eating mammals), the larvae emerging from their eggs has to develop and propagate in a first intermediate host (usually a snail), and the cercarial stages produced in the snail must then encyst as metacercariae in or on a second intermediate host (fish). The life cycle is completed when infected fish is ingested by the definitive host. Transmission of these heterophyids takes place where all the hosts co-occur. Fish infection occurs via skin penetration by infective cercariae. Infection of humans with the intestinal fluke Heterophyes heterophyes is acquired by ingestion of www.elsevier.com/locate/vetpar Available online at www.sciencedirect.com Veterinary Parasitology 151 (2008) 196–202 * Corresponding author at: Division of Veterinary Medicine, The School of Veterinary Medicine and Science, The University of Not- tingham, College Road, Sutton Bonington Campus, Leicestershire LE12 5RD, United Kingdom. Tel.: +44 115 951 6445; fax: +44 115 951 6440. E-mail address: Hany.Elsheikha@nottingham.ac.uk (H.M. Elsheikha). 0304-4017/$ – see front matter # 2007 Elsevier B.V. All rights reserved. doi:10.1016/j.vetpar.2007.10.021