Echinococcus species, neglected food borne parasites: taxonomy, life cycle and diagnosis

Abstract

Echinococcosis is a parasitic disease caused by a cestode belonging to the genus Echinococcus. These are small tapeworms belonging to the phylum Plathelmintes, family Taeniidae, class Cestoda with a worldwide distribution from the North Hemisphere to the tropics. The biology of the parasite and the transmision patterns offer enough reasons to consider the species of this genus (Echinococcus) as food borne parasites. The adult stage of the worm lives in the digestive tract of the definitive host(canids, felids, hyenids), these are able to excrete infected eggs in the environment. The intermediate host (usually herbivores, ungulates and accidental human) become infected through ingestion of the cestodes eggs. The metacestodes develope in the body of the intermediate host, in different organs(liver and lung most frequent) where are described cystic, policystic and alveolar echinococcosis. The diagnosis of the disease is based on the screening and confirmatory methods. The imagery is an important tool that has to be combined with serology for incresing the accuracy of the diagnostic. The level of the hygene, the proximity with domestic animals and ocupation are important opportunities for the transmission of the parasite. Human echinococcosis is a neglected parasitic disease which ask more attention and improvments to the the diagnostic tools.