Hymenolepiasis is a cosmopolitan parasitosis caused by a hymenolepidid tapeworm infection, most commonly <i>Hymenolepis nana</i>, that is reported worldwide but particularly in tropical and subtropical countries and which is usually asymptomatic but in severe cases can also manifest with nausea, abdominal pain, anorexia, diarrhea and overall weakness. [from
ORDO]