Echinococcus multilocularis infection

What is Echinococcus multilocularis infection?

Echinococcus multilocularis (E. multilocularis) infection is caused by eating the eggs of tapeworms called E. multilocularis. 

These tapeworms can cause disease in humans and animals.

They are often found in the intestines of dogs, wild canines (e.g., coyotes, foxes, wolves), and rodents. This is more common in other parts of the world. 

More recently, it has been identified in animals living in Ontario and parts of the United States of America.

Photo of a dog and a fox

What are the symptoms of E. multilocularis?

Symptoms depend on the type of tapeworm and the body part it infects.  The eggs hatch and move into the liver, lungs, and other areas of the body, such as the bone and intestines.  They grow into large closed sacs called cysts.  These cysts continue to grow and may spread elsewhere in the body.  This infection can be confused with cancer.  Symptoms may include:

  • Pain in and around infected area
  • Tiredness
  • Jaundice (yellowing of the skin and the whites of the eyes)
  • Fluid in the abdomen, causing swelling (ascites)

It can take 5 to 15 years after the eggs enter your body before you feel sick.  E. multilocularis infection is a slowly progressing disease that can become very serious if untreated.

How does E. multilocularis spread?

E. multilocularis spreads mostly from animal to person through the “fecal-oral route” by:

  • Putting anything in your mouth that is contaminated by the feces (poop) of infected animals, such as food or water.
  • Touching your mouth after touching contaminated surfaces or feces of infected animals. 

Hunters are most at risk because of their exposure to wild animals.  Children are also at risk because they play with dogs and are more likely to have poor hand hygiene. 

How long is it contagious?

E. multilocularis does not spread from person to person.  The eggs can survive in a wet environment at temperatures of 4oC (39.2F) and above for one year.  If eaten during this time, it can cause disease.

How is E. multilocularis treated?

If you or your child has these symptoms, see a health care provider as soon as possible.  Tell your health care provider if you lived in an area where the tapeworms are common and live, work, or play with dogs and wild canines.  Treatment depends on where the infection is.  It may include removal or drainage of the cysts and antihelmintic medications (medications that kills worms).

How do I prevent the spread of E. multilocularis?

Ways to prevent infection include:

  • Wash your hands often for at least 15 seconds with warm water and soap, especially before and after preparing foods, before eating, and after handling pets and their feces.
  • Practice safe food handling, including washing and peeling all uncooked fruits and vegetables in clean water.  Avoid eating undercooked meat and drinking untreated water.
  • Avoid exposure to feces from wildlife.
  • Hunters and trappers, especially those working with wild canines, should wear plastic gloves when handling these animals.
  • Try to prevent your pets from eating feces, contaminated (uncooked) meat, and wild animals.  Talk to your veterinarian to see if your pets are at risk for exposure and if regular treatment is needed.
Photo of a person washing their hands

For more information contact the Health Unit or speak to your health care provider.


American Academy of Pediatrics. (2018). Red book: 2018-2021 Report of the committee on infectious diseases (31st ed.). D.W. Kimberlin, M.T. Brady, M.A. Jackson, & S.S. Long (Eds.). Itasca, IL.

Heymann, D.L. (Ed.). (2015). Control of communicable diseases manual (20th ed.). Washington, DC: American Public Health Association.

Ontario Ministry of Health and Long-Term Care. (2018). Infectious Diseases Protocol: Appendix A – Echinococcus multilocularis infection. Toronto, ON: Queen’s Printer for Ontario.