Infectious Forms of Parasites in Food:Man Embedded in Ecosystems

摘要

Foodborne parasites have usually environmental infectious stages. In developing countries, high concentrations of parasite infectious forms contaminate the environment entailing high prevalence of foodborne parasitic diseases with significant impact on health and economy. Complex interactions among exposure to contaminated food and water, disease, poverty and malnutrition take place. In developed countries, food- or waterborne parasitic infections keep also a considerable importance, as shown by the persistence of infectious water- or foodborne outbreaks and the occurrence of infections due to emergent or reemergent eukary-otic pathogens. Since parasite infections are usually rare in developed areas, a breakdown in prevention measures and specific health staff training often occur. Most emerging or reemerging parasite species are agents of foodborne infections. Considering only parasite "protists", most emerging or reemerging species can be foodborne, waterborne or contagious as Giardia, Cryptosporidium species or,likely, Microsporidia. These pathogens belong to taxonomically unrelated Eukaryotic groups but they share common features: (a) mostly monoxenous; (b) ubiquitous; (c) challenging taxonomy; (d) unclear notions on transmission, infection source or reservoir; (e) highly resistant infectious life stages; (f) lack of efficient experimental models; (g) uncertain pathogenic power to immunocompetent hosts. Regarding emerging or reemerging helminthes, those transmitted by foodborne route are: Anisakis simplex, Echinococcus granulosus, Diphyllobothrium species, Metorchis conjunctus, Taenia solium and Trichinella spiralis. To consume exotic meals could increase foodborne parasitic risk in Europe. Although common representations of human daily life show a humanity that has in some way "escaped" from ecosystems, men take on their role of top level consumers, and are therefore exposed to the associated highly diversified parasitological risk.