Hymenolepiasis is infestation by one of two species of tapeworm : or .

Alternative Names

Dwarf tapeworm infection; Rat tapeworm; Tapeworm - infection

Causes, incidence, and risk factors

Hymenolepis live in warm climates and are common in the southern United States. Insects eat the eggs of these worms.

Humans and other animals become infected when they intentionally or unintentionally eat material contaminated by insects. In an infected person, it is possible for the worm's entire life cycle to be completed in the bowel, so infection can last for years.

infections are much more common than infections in humans. These infections used to be common in the southeastern United States, in crowded environments and in people who were confined to institutions. However, the disease occurs throughout the world.


Symptoms occur only with heavy infections. Symptoms include:

  • Diarrhea
  • Gastrointestinal discomfort
  • Itchy anus
  • Poor appetite
  • Weakness

Signs and tests

Examination of the stool for eggs confirms the diagnosis.


The treatment for this condition is a single dose of praziquantel, repeated in 10 days.

Support Groups

Expectations (prognosis)

Expect full recovery following treatment.


  • Abdominal discomfort
  • from prolonged diarrheaDehydration

Calling your health care provider

Call your health care provider if chronic diarrhea or abdominal cramping are present.


Good hygiene, public health and sanitation programs, and elimination of rats help prevent the spread of hymenolepiasis.


Blanton R. Adult tapeworm infections. In: Kliegman RM, Behrman RE, Jenson HB, Stanton BF, eds. . 19th Ed. Philadelphia, Pa: Saunders Elsevier; 2011: chap 294.

Richardz FO Jr. , , and species. In: Long SS, ed. . 3rd ed. Philadelphia, Pa: Churchill Livingstone Elsevier; 2008: chap: 279.

Encyclopedia content is provided as information only and not intended to replace the advice and instruction from your personal physician.