The kinetics of antibody response to intraperitoneal infection of mice with third stage larvae of Anisakis simplex was investigated by ELISA. Maximum antibody response to excretion-secretion (ES) antigens was reached before maximum response to somatic (SA) antigens. Total immunoglobulin (Ig) production (consisting mainly of IgM and IgG1 isotypes) was very similar in both cases. Immunoblotting was used to characterize the antigens recognized by the host in the presence or absence of the metabolic products released by the parasite in vivo. Sera from mice infected with live larvae (anti-L3 L serum) and immunized with dead larvae (anti-L3 D serum) recognized a similar pattern of bands in immunoblots of ES and SA antigen preparations. In the latter, however, three bands at 14, 17 and 18 kD were only recognized by the anti-L3 L serum. A possible explanation is that these low molecular weight antigens are ES products released only in vivo. Finally, the immune response in mouse was compared using ELISA and immunoblotting with the response of a human anisakiasis reference serum, and was found to display considerable similarities. This suggests that the mouse may be a useful model for studying the immunobiology of A. simplex in man.

Various anthelmintics belonging to different pharmacological groups (ivermectin, clorsulon, closantel, netobimin, febantel, praziquantel, niclofolan, bithionol, trichlorfon, levamisole hydrochloride, piperazine citrate and dihydrochloride, nitroscanate), all of proven efficacy against certain helminths, were tested and compared for their in vivo and in vitro activity on a natural infection of Oncorhynchus mykiss by Gyrodactylus, probably G. salaris. The trout were also observed for signs of toxic reaction to the drugs. Complete efficacy (100 % reduction) with no toxic effects was achieved only by bithionol (20 mg I-') and nitroscanate (0.07 mg 1-l).

In this study, we evaluate the MM3-COPRO method for detection of Fasciola coproantigens in human fecal samples, and the usefulness of a new preservative/diluent, CoproGuard, developed for preservation of Fasciola coproantigens. The MM3-COPRO assay was evaluated with 213 samples from healthy patients, 30 Fasciola positive fecal samples (according to the Kato-Katz method), and 83 samples from patients with other parasitic infections. All Fasciola positive specimens were detected with the MM3-COPRO assay (100% sensitivity) and there was no cross-reactivity with other common parasites present in the clinical specimens analyzed (100% specificity). The use of CoproGuard enhanced coproantigen extraction without affecting the detection limit of the assay, and the antigenicity of Fasciola coproantigens in fecal samples stored at 37 degrees C was retained throughout the entire observation period (120 days). We concluded that the MM3-COPRO ELISA combined with the use of CoproGuard may be a very useful tool for the diagnosis of human fascioliasis.

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To investigate antigenic differences between the developmental stages of Anisakis simplex, somatic, excretion–secretion and detergent-solubilized surface antigen preparations of third- and fourth-stage A. simplex larvae, and a somatic antigen preparation of adults, were characterized by SDS–PAGE and immunoblotting using mouse immune serum containing antibodies against the two larval stages. Excretion–secretion and surface antigen preparations from thirdstage larvae behaved very differently from those of fourth-stage larvae, in both SDS-PAGE and immunoblotting; this suggests that certain excretion–secretion and surface antigens are highly stage-specific. By contrast, somatic components of third- and fourth-stage larvae were found to have very similar banding patterns, suggesting conservation of these components during the development of the parasite in mice. The SDS-PAGE and immunoblotting results for adult somatic components seem to support this hypothesis