A Review of the Genus Echinococcus Rudolphi, 1801.

During a recent investigation in Kenya, Echinococcus adults were obtained from 25 domestic dogs (Canis familiaris), three hyaenas (Crocuta crocuta), three wild hunting dogs (Lycaon pictus), and a jackal (Thos mesomelas) (Nelson and Rausch, 1963). In view of the occurrence of several species of Echir.JCOCCUS reported from South Africa by Cameron (1926) and by Ortlepp (1934, 1937), a detailed study was necessary before the specific status of the Kenya material could be determined. We were fortunate in having available reference material from various parts of the world. As a result of this study it is concluded that only three of the I I named species of Echinococcus can be distinguished by purely morphological criteria, six are regarded as synonyms of E. granulosus (Batsch, 1786), and the status of two is uncertain. was not discussed. More recent studies indicate that some of these earlier conclusions were erroneous. This species has become widely distributed as a result of the extensive movement of domesticated animals. It is indigenous at high latitudes on the North American and Eurasian continents, where the life-cycle involves the wolf (Canis lupus) and various species of deer. A variable anatomy has been observed in both adults and larvae. Some of the variations recorded in the strobilar stage may have resulted from different methods of collection and preservation, and those in the larval stage are partly due to the effect of different host species. Among the possibly existing biological strains of E. granulosus only now being investigated, one, E. granulosus canadensis Cameron, 1960, has been named on the basis of its peculiar host-parasite relationships and possible serological differences. Measurements and morphological data for E. granulosus are summarized in Table 1. Further data are to be found in the comparative study of material from Kenya (Nelson and Rausch, 1963). In the strobilar stage this species is distinguished by the number and distribution of the testes, by the position of the genital pore, and by the form of the gravid uterus