Perspectives on intestinal tapeworm infections: An evaluation of direct and indirect life-cycles with a special emphasis on species of .

Numerous experimental studies have been conducted on the rodent tapeworm, . In contrast, less is known about the life-cycle and immunobiology of the zoonotic dwarf tapeworm, . However, appears to be unique in that; (i) it can complete its entire life-cycle within a single mammalian host, and (ii) cysticercoids that develop in beetle intermediate hosts are tailed, while those that develop in the intestinal tissue of mammals are tailless. This is in contrast to all other spp., which only appear to develop tailed cysticercoids in beetles or experimentally infected immunodeficient rodents. Even though and are phylogenetically much closer to each other than to , when mice with severe combined immunodeficiency (SCID) were inoculated with eggs, hatched oncospheres invaded the intestinal tissue and developed into infective tailed cysticercoids in approximately 11 days. Therefore, appears to be truly unique in its ability to develop tailed cysticercoids in beetles and tailless cysticercoids in mammals. These unique evolutionary characteristics are discussed in relation to other cyclophyllidean cestodes, including and spp.