What is hydatid tapeworm (Echinococcus granulosus)?

Echinococcus granulosus is a tapeworm parasite, the larval form of which causes hydatid disease in people, but also infects a very wide range of other mammals. Hydatid disease causes large parasite cysts to develop in internal organs, mainly in the liver and lungs, and occasionally the brain. As the cysts grow they may cause pain, exercise intolerance, weakness and sudden death if ruptured.

 

Hydatid tapeworm profile

The adult hydatid tapeworm is small, ranging from 3mm – 6mm in length, and lives in the intestines of carnivorous animals, such as dogs or dingoes. The tapeworm develops into larval cysts in hosts such as sheep, cattle, goats, pigs, horses, kangaroos, wallabies or occasionally humans.

 

How is the hydatid tapeworm spread?

The hydatid tapeworm was brought to Australia when sheep were introduced by European settlers. Animals digest the tapeworm eggs when eating pasture, or in the case of people, by contact with infected dogs.

Dogs become infected when they eat the organs of infected livestock or wild animals, particularly the liver and lung, which contain the larval, hydatid cysts. The cysts then develop into adult tapeworms.

In the Perth Hills it is likely that the parasite was introduced with dogs used for pig and kangaroo hunting, as the adult tapeworm has been found in hunters’ dogs. Domestic dogs can become infected by scavenging the carcasses of dead kangaroos and pigs. People can be infected by the accidental consumption of soil, water, or food that has been contaminated by the faeces of an infected dog or infected eggs on the dog’s coat.

 

Is this a problem for wildlife?

Although hydatid disease is rare in people in Western Australia, one study in state forest bordering Perth found a high frequency of the disease in kangaroos, with 29% (n=21) of animals infected, and feral pigs (n=24), with 46% of animals infected. Cysts may seriously impair the ability of marsupials, particularly small species of wallabies, to breathe, exposing them to the risk of predation. This is a serious conservation issue, particularly for species that live in isolated populations.

 

Did you know:

  • Echinococcus eggs can stay viable in the soil for up to a year.
  • Infected dogs will have some Echinococcus eggs sticking to their fur.
  • Echinococcus is found almost worldwide.

 

Download the ‘Hyatid Tapeworm and Wildlife’ information sheet.