Hymenolepis

n.

a genus of small widely distributed parasitic tapeworms. The dwarf tapeworm, H. nana, only 40 mm in length, lives in the human intestine. Fleas can be important vectors of this species, and children in close contact with flea-infested dogs are particularly prone to infection. H. diminuta is a common parasite of rodents; humans occasionally become infected on swallowing stored cereals contaminated with insect pests – the intermediate hosts for this parasite. Symptoms of abdominal pain, diarrhoea, loss of appetite, and headache are obvious only in heavy infections of either species. Treatment involves a course of anthelmintics.