Studies on Echinococcus alveolaris (Klemm, 1883), from St. Lawrence Island, Alaska. I. Histogenesis of the Alveolar Cyst in White Mice

Abstract

Although Virchow (1855) established the helminthic nature of alveolar cysts, very little experimental work has been done on this parasite type. This has been due mainly to the consistent failure in producing alveolar cysts in experimental animals and, until recently, man and, rarely, ox were thought to be the only intermediate hosts for alveolar echinococcosis. The inadequate information concerning this parasite has led to many lengthy controversies regarding the taxonomy of the species involved. Rodents from the Commander Islands were first reported as intermediate hosts for alveolar echinococcosis by Barabash-Nikiforov (1938). Later Rausch and Schiller (1951) reported the parasite from the same host in the western part of St. Lawrence Island. Echinococcus alveolaris Klemm on St. Lawrence Island, Alaska has been recorded from the common mole (Microtus oeconoius Pallas) and the red-backed mouse (Clethrionomys rutilus Pallas). Thomas et al (1954) reported cases of natural infection in the ground squirrel (Citellus undulatus Pallas) and in shrews (Sorex jacksoni Hall and Gilmore). The natural infection in rodents suggested the possibility of using mice as laboratory hosts. White mice were successfully infected and studies of the histogenesis and histopathology of the cysts undertaken. The histopathology will be the subject of another publication.