Echinococcosis / Hydatidosis

Human echinococcosis is a parasitic disease caused by tapeworms of the genus Echinococcus.

The two most important forms of the disease in humans are cystic echinococcosis (hydatidosis) and alveolar echinococcosis. Humans are infected through ingestion of parasite eggs in contaminated food, water or soil, or through direct contact with animal hosts.

Echinococcosis is often expensive and complicated to treat and may require extensive surgery and/or prolonged drug therapy. Prevention programs focus on the deworming of dogs and sheep, which are the definitive hosts. In the case of cystic echinococcosis, control measures also include improved food inspection, slaughterhouse hygiene, and public education campaigns. The vaccination of lambs is currently being evaluated as an additional intervention.

More than 1 million people are affected with echinococcosis at any one time.

Key facts

Human echinococcosis is a zoonotic disease (a disease that is transmitted to humans from animals) that is caused by parasites, namely tapeworms of the genus Echinococcus. Echinococcosis occurs in 4 forms:
cystic echinococcosis, also known as hydatid disease or hydatidosis, caused by infection with Echinococcus granulosus; alveolar echinococcosis, caused by infection with E. multilocularis; polycystic echinococcosis, caused by infection with E. vogeli; and unicystic echinococcosis, caused by infection with E. oligarthrus.

The two most important forms, which are of medical and public health relevance in humans, are cystic echinococcosis (CE) and alveolar echinococcosis (AE).

What PAHO does

Initiative for the control of cystic echinococcosis

Hydatidosis, or cystic echinococcosis, is an important zoonosis for the Region, since it registers a significant frequency in many countries of the continent, with a different presentation burden, affecting mainly dogs (in the form of definitive hosts), cattle, sheep and pigs (intermediate hosts) and particularly the health of humans. Its impact, although manifest, is not sufficiently measured. Its presentation, in each latitude, is very influenced by the differences of its ecosystems, but also by the form and intensity in the approach of the problem, usually avoiding the interdependencies that surpass the physical borders of the nations.

The implementation of the Southern Cone Subregional Surveillance and Control of Hydatidosis Project: Argentina, Brazil, Chile and Uruguay, is part of a mandate that PAHO/WHO received from its Member States, beginning with the 12th Interministerial Meeting on Health and Agriculture (RIMSA), held in São Paulo, Brazil, in the year 2001.

The fact that several meetings have been completed already expresses the importance and represents the efforts that countries are giving to the subject. But there are other aspects that deserve to be highlighted, such as the adequate vision to recognize the problem from a plural point of view, with the need for joint and integrated efforts, between countries, between sectors and disciplines, and supported by technical cooperation agencies that they complement in their functions.

There have been achievements. However, we make it a matter of highlighting some of them, precisely because of their importance, as fundamental points for adapting and guiding interventions and future initiatives to combat hydatidosis in the Region, such as:

  • the need to strengthen the participation of civil society in the processes of struggle, often understood and assumed as actions of exclusive responsibility and official decision;
  • improve knowledge and evidence of the economic impact of hydatidosis on health and society;
  • cross-border actions;
  • the adequate and sufficient training of human resources;
  • the need to adopt rigorous evaluations of the plans, especially with external collaboration to the services themselves;
  • the use of the powerful instrument of communication to mobilize society.

PAHO supports the application of new lessons and advances new initiatives to strengthen the responsibility of each country and incorporate effective and innovative proposals.