TAENIA-SOLIUM - DESCRIPTION OF THE INTESTINAL IMPLANTATION SITES IN EXPERIMENTAL HAMSTER INFECTIONS

Experimental infections in golden hamsters with viable Taenia solium m etacestodes were used to study by light and electron microscopy the im plantation site of the adult tapeworm in the intestinal wall. Implanta tion sites from 3-, 4-, 10-, and 40-day infections were located in the upper third of the duodenum, excised and fixed in Zenker's or Karnovs ky's solution, embedded in Polybed resin, and sectioned longitudinally to observe the position of the worm on the intestinal wall. The scole x of the tapeworm was situated between host villi, with the rostellum penetrating the intestinal wall and the suckers entrapping adjacent vi lli. Serial sections through several whole implantation sites revealed that the worm was anchored to the host by all 4 suckers simultaneousl y, each of which was located at a different level and had entrapped in testinal villi in its cavity. Host tissue within the suckers was damag ed, exhibiting various degrees of cell lysis and necrosis of epithelia l and submucosal cells. The tegumentary surface and microtriches of th e scolex were well preserved, with occasional coalescence of tegumenta ry microvesicles in 10- and 40-day-old infections; microtriches were i n direct contact with the damaged host tissue. This study is the first morphological and ultrastructural description of the attachment of T. solium to the intestinal wall employing an experimental model, the re sults of which may contribute to a better understanding of the biology of human tapeworm infections.