Dwarf tapeworm refers to -

HYMENOLEPIS NANA Commonly known as the dwarf tapeworm, Hymenolepis nana is the smallest and the most common tapeworm found in the human intestine. The name Hymenolepis refers to the thin membrane covering the eggand nana to its small size (nanus--dwarf). It is cosmopolitan in distribution but is more common in the warm than in cold climates. Infection is most common in school children and institutional populations. It is unique that it completes its life cycle in one host, the parasite being maintained by transmission between humans, and even in a single individual, who can act as both the definitive and intermediate host REF:TEXTBOOK OF MEDICAL PARASITOLOGY;CKJ PANIKER;6TH EDITION;PAGE NO 155