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A.D.A.M. Medical Encyclopedia [Internet]. Atlanta (GA): A.D.A.M.; 2013.

A.D.A.M. Medical Encyclopedia.

Hymenolepiasis

Dwarf tapeworm infection; Rat tapeworm; Tapeworm - infection

Last reviewed: September 1, 2013.

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

Causes

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 (including fleas associated with rats). 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.

Hymenolepis nana infections are much more common than Hymenolepis diminuta 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

Symptoms occur only with heavy infections. Symptoms include:

  • Gastrointestinal discomfort
  • Itchy anus
  • Poor appetite
  • Weakness

Exams and Tests

Examination of the stool for eggs confirms the diagnosis.

Treatment

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

Outlook (Prognosis)

Expect full recovery following treatment.

Possible Complications

  • Abdominal discomfort
  • Dehydration from prolonged diarrhea

When to Contact a Medical Professional

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

Prevention

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

References

  1. Blanton R. Adult tapeworm infections. In: Kliegman RM, Behrman RE, Jenson HB, Stanton BF, eds. Nelson Textbook of Pediatrics. 19th Ed. Philadelphia, PA: Saunders Elsevier; 2011:chap 294.
  2. Richardz FO Jr. Diphyllobothrium, Dipylidium, and Hymenolepsis species. In: Long SS, ed. Principles and Practice of Pediatric Infectious Diseases. 3rd ed. Philadelphia, PA: Churchill Livingstone Elsevier; 2008:chap: 279.

Review Date: 9/1/2013.

Reviewed by: Jatin M. Vyas, MD, PhD, Assistant Professor in Medicine, Harvard Medical School; Assistant in Medicine, Division of Infectious Disease, Department of Medicine, Massachusetts General Hospital. Also reviewed by David Zieve, MD, MHA, Bethanne Black, and the A.D.A.M. Editorial team.

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The information provided herein should not be used during any medical emergency or for the diagnosis or treatment of any medical condition. A licensed medical professional should be consulted for diagnosis and treatment of any and all medical conditions. Call 911 for all medical emergencies. Links to other sites are provided for information only — they do not constitute endorsementscof those other sites. © 1997–2011 A.D.A.M., Inc. Any duplication or distribution of the information contained herein is strictly prohibited.

Copyright © 2013, A.D.A.M., Inc.

A.D.A.M., Inc. is accredited by URAC, also known as the American Accreditation HealthCare Commission (www.urac.org). URAC's accreditation program is an independent audit to verify that A.D.A.M. follows rigorous standards of quality and accountability. A.D.A.M. is among the first to achieve this important distinction for online health information and services. Learn more about A.D.A.M.'s editorial policy, editorial process and privacy policy. A.D.A.M. is also a founding member of Hi-Ethics and subscribes to the principles of the Health on the Net Foundation (www.hon.ch).

The information provided herein should not be used during any medical emergency or for the diagnosis or treatment of any medical condition. A licensed medical professional should be consulted for diagnosis and treatment of any and all medical conditions. Call 911 for all medical emergencies. Links to other sites are provided for information only — they do not constitute endorsementscof those other sites. © 1997–2011 A.D.A.M., Inc. Any duplication or distribution of the information contained herein is strictly prohibited.

Copyright © 2013, A.D.A.M., Inc.

Figures

  • Digestive system organs.

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