• The most common way people become infected is via the fecal oral route through accidental ingestion of feces that is contaminated with hymenolepis nana eggs. This infection is found in all parts of the world with central Europe and Latin America being hardest hit. Although rare, hymenolepiasis is usually found in the south eastern portion of the U.S. H. nana infections are most common in areas that have temperate climate zones.
  • Children are the most vulnerable to this parasite making nursery schools ideal environments for the spread of the infection. An often referenced study in Zimbabwe conducted in 1994 gives some insight into how the infection spreads. The study found that hymenolepiasis is higher in urban areas than in rural areas. The study came to the conclusion that intrafamily transmission was the primary mode of infection in urban areas while in rural areas the infection was more prevalent among younger, school age children.
  • One estimate places the number of world-wide infections at 20 million, but rates vary regional. In 1987, only 1% of American school children were positive for the infeciton. In other parts of the world, such as Argetina, the rates are much higher with 26% of school children identified as having the infection.
  • Unless a severe case is allowed to develop most infections are asymptomatic. With extreme infections, however, a person may experience general symptoms such as abdominal pain, diarrhea, headache, and overall weakness.
  • A single dose of Praziquantel is usually very effective. To prevent contracting the disease, one should increase their hygiene practices and establish extra cautionary measures when dealing with human waste products..



CDC Division of Parasitic Diseases. Public Information: Fact Sheet. 22 Nov. 2004. 4 June 2005 <>
Mason PR and Patterson BA. "Epidemiology of Hymenolepis nana infections in primary school children in urban and rural communities in Zimabwe. J. Parasitol." 80: 245-50, 1994.
Markell, Edward et al. Medical Parasitology. Philadelphia, PA: Sanders, 1999.
Tolan, Robert Jr. eMedicine. 18 Dec. 2003. 4 June 2005 <>.