Shellfish parasites

Taylor Q) found the endoparasitic dinoflagellate Amoebophrya ceratii in phytoplankton samples taken in 1965 from Sequim Bay, Washington (Figure 1). He reported that 30-40% of the G. catenella cells in 3 samples taken at intervals over 4 months were infested by this parasite. He suggested that the parasite offered a remote possibility of biological control of catenella, the causative organism of many of the outbreaks of paralytic shellfish poisoning (PSP) on both sides of the North Pacific (2, 3, 4, and in the Southern Hemisphere (j6). 

In order to assess the potential value of Amoebophrya in reducing problems of PSP in shellfish, it will be necessary to determine whether the parasite destroys or retains the toxins as it kills the Gonyaulax cells. 

While all humans have IgE antibodies fhaf are involved in defense against parasitic infections, only humans who are predisposed to the development of allergies will produce IgE antibodies upon exposure fo certain protein allergens present in their environment including their diet. Only a few of the many proteins found in foods are capable of sfimulating the production of specific IgE antibodies in susceptible individuals (Taylor, 2002). With molluscan shellfish, only one, or perhaps a few, of the numerous proteins is known to provoke the production of IgE antibodies that specifically recognize one or more species of molluscan shellfish. 

Angiostrongylus cantonensis Parasitic worm found in uncooked molluscs, shellfish 2 Minimum effective dose... 

III. Association of Human Waterborne Parasites and Molluscan Shellfish... 

IV. Methods Used for Identification of Human Protozoan Parasites in Molluscan Shellfish... 

III. ASSOCIATION OF HUMAN WATERBORNE PARASITES AND MOLLUSCAN SHELLFISH... 

REPORTS OF HUMAN WATERBORNE INTESTINAL PARASITES IN FERAL MOLLUSCAN SHELLFISH (CHRONOLOGICAL ORDER)... 

EXPERIMENTAL EXPOSURE OF MOLLUSCAN SHELLFISH TO TRANSMISSIBLE STAGES OF HUMAN INTESTINAL WATERBORNE PARASITES... 

Shellfish species Reference Parasite species Comments... 

IV. METHODS USED FOR IDENTIFICATION OF HUMAN PROTOZOAN PARASITES IN MOLLUSCAN SHELLFISH... 

Methods for identification of human protozoan parasites in the tissue of molluscan shellfish include (1) immunofluorescent antibodies (IFA) alone or in combination with immunomagnetic separation (IMS), (2) polymerase chain reaction (PCR) alone or combined with restricted fragment length polymorphism (RFLP) for genotyping, (3) multiplexed nested PCR, and (4) fluorescence in situ hybridization (FISH). Infectivity of the parasites recovered from the shellfish are usually assessed by mouse bioassays. 

Development of new molecular techniques that can be applied to a wide variety of food items has dramatically increased the sensitivity and specificity of detection of human enteric parasites in the tissue of molluscan shellfish (Schwab et al., 1998, 2000 citations in Table I). 

Graczyk, T.K. 2003a. Human protozoan parasites in molluscan shellfish Epidemiology and detection. In Molluscan Shellfish Safety (A. Villalba, B. Requere, J.L. Romalde, and R. Beiras, eds), pp. 397-405. Conselleria de Pesca e Asuntos Maritimos, Hunta de Galicia, Spain. 

Graczyk, T.K. 2003b. Human waterborne parasites in molluscan shellfish. J. Parasitol 89, S57-S61. 

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