PREVALENCE AND PATHOLOGICAL ASPECTS TO DI PHYLLOBOTHRIASIS IN RETURNING SALMON, ONCORHYNCHUS-KISUTCH, TO COYHAIQUE, 11TH REGION, CHILE

The presence of plerocercoids of Diphyllobothrium sp. in salmon return ing from the ocean to Coyhaique (45-degrees-35'S, 72-degrees-07'W), Ch ile, are reported for the first time. Twenty-one out of 30 adult fish examined were parasited with plerocercoids. Morphological characterist ics are similar to Diphyllobothrium pacificum, a common zoonotic paras ite in Chilean and Peruvian marine fish. Experimental infection in def initive hosts such as dogs, is necessary in order to identify the para site to a specific level. Plerocercoids in the mucosa, muscular layers and serosa of stomach induced moderate vacuolar degeneration. An incr ease in the number of granular eosinophilic cells of the compact strat um was observed in muscular layers and in the corion of the mucosa ass ociated to plerocercoids; all surrounded by a fibroblastic reaction. A rterial vessels presented hypertrophia of the muscular layer and degen erative injury of endothelial cells, with citoplasmatic vacuolization.