Skip navigation

Echinococcus

Echinococcus is an infection caused by the Echinococcus granulosus or Echinococcus multilocularis tapeworm. The infection is also called hydatid disease.

Causes

Echinococcus is common in:

  • Africa
  • Central Asia
  • Southern South America
  • The Mediterranean
  • The Middle East

In the United States, the disease is very rare. But it has been reported in California, Arizona, New Mexico, and Utah.

Humans become infected when they swallow eggs in contaminated food. The infection is carried to the liver, where cysts form. Cysts can also form in the:

  • Brain
  • Bones
  • Kidney
  • Lungs
  • Skeletal muscles
  • Spleen

Risk factors include being exposed to:

  • Cattle
  • Deer
  • Feces of dogs, wolves, or coyotes
  • Pigs
  • Sheep

Symptoms

A liver cyst may produce no symptoms for 10 to 20 years, until it is large enough to be felt by physical examination.

Symptoms include:

Exams and Tests

A physical examination may show signs of:

  • Abdominal pain
  • Problems with the skin and other organs
  • Shock

The following tests may be done to find the cysts:

Most often, echinococcosis is found when an imaging test is done for another reason.

Treatment

Many patients can be treated with anti-worm medicines.

The cysts may be removed with surgery, if possible. But this can be a complicated surgery.

Outlook (Prognosis)

If the cysts respond to oral medication, the likely outcome is good.

Possible Complications

The cysts may break open (rupture) and cause severe illness, including:

  • Fever
  • Low blood pressure
  • Shock

The cysts may also spread throughout the body.

When to Contact a Medical Professional

Call your health care provider if you develop symptoms of this disorder.

Prevention

In areas where the disease is known to occur, health education and routinely removing tapeworms from dogs can help prevent the disease.

Alternative Names

Hydatidosis; Hydatid disease, Hydatid cyst disease

References

King CH, Fairley JK. Cestodes (tapeworms). In: Mandell GL, Bennett JE, Dolin R, eds. Principles and Practice of Infectious Diseases. 7th ed. Philadelphia, PA: Elsevier Churchill Livingstone; 2009:chap 29.

Update Date: 8/30/2014

Updated by: Neil K. Kaneshiro, MD, MHA, Clinical Assistant Professor of Pediatrics, University of Washington School of Medicine, Seattle, WA. Also reviewed by David Zieve, MD, MHA, Isla Ogilvie, PhD, and the A.D.A.M. Editorial team.

A.D.A.M Quality Logo

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 physician 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 endorsements of those other sites. Copyright 1997-2014, A.D.A.M., Inc. Duplication for commercial use must be authorized in writing by ADAM Health Solutions.

A.D.A.M Logo