a1 Zoonotic Disease Section, Arctic Health Research Center, Public Health Service, U.S. Department of Health, Education, and Welfare, Anchorage, Alaska
It is concluded that E. sibiricensis is the etiologic agent of alveolar hydatid disease in man. The cestode has a wide distribution in Eurasia, and St Lawrence Island apparently represents the north-easternmost extent of its range. The study of the cestode in Europe has been complicated by the co-existence of E. granulosus, which does not occur on St Lawrence Island. Microtine rodents, particularly Microtus spp. and Clethrionomys rutilus, are the natural intermediate hosts of this cestode, although other species of mammals, including man, are parasitized with varying degrees of success on the part of the larval cestode.
(Received July 09 1955)