Molecular genetic variation in Echinococcus and Taenia: an update.

An update on our understanding of molecular variation in Echinococcus and Taenia is provided. Genetic variation within certain species of Echinococcus is now a well accepted phenomenon and a number of intraspecific variants or strains of E. granulosus, in particular, have been characterized hitherto using a range of procedures. Newly acquired molecular information has now been used in epidemiological studies with E. granulosus and in phylogenetic analysis of the genus Echinococcus. Similarly, DNA approaches have been applied for taxonomic characterization of the recently recognized Asian Taenia, a third form of human Taenia, which occurs in Southeast Asia, and which is distinguishable from, but closely related to, Taenia saginata.