Your Guide to
Neglected Tropical Diseases

Echinococcosis is a parasitic disease caused by tapeworms that form slow-growing cysts in organs, primarily the liver and lungs. There are two main forms: the common form (majority of cases) and a more severe form. The disease often remains silent for years as cysts develop slowly in affected organs.

Symptoms vary depending on cyst location: liver cysts may cause abdominal pain and jaundice, while lung cysts cause coughing and chest pain. If a cyst ruptures, it can trigger severe allergic reactions. The severe form is usually fatal without treatment, while the common form causes significant disability and requires complex, expensive treatment that often involves surgery.

People ingest tapeworm eggs from infected dog/fox feces through contaminated soil, dog fur, food, or water. Dogs get tapeworms from eating infected livestock organs. Eggs hatch in the intestines and larvae travel through the blood to organs and form cysts. The disease does not spread from person-to-person. The common form typically cycles between dogs and sheep, while the severe form usually cycles between foxes and small rodents, though dogs can carry this form as well.

Geographic scope:

• The common form is on every continent except Antarctica, with highest rates in pastoral regions.
• The severe form occurs only in the Northern Hemisphere, including parts of Europe, Asia, and North America.
• Endemic in Central Asia, Mediterranean regions, parts of South America (especially Argentina and Peru), East Africa, and western China.
• In Japan, Echinococcosis is primarily found in Hokkaido.

Population affected:

• More than 1 million people are currently infected worldwide.
• Approximately 148,000 new cases annually.
• More than 1,300 deaths per year globally.
• Primarily affects pastoral communities where dogs interact closely with livestock.
• Children are particularly vulnerable due to close contact with dogs and inconsistent handwashing.

Treatment depends on cyst size, location, and type. Albendazole medication cures about 30% of small, simple cysts. The PAIR procedure (Puncture, Aspiration, Injection and Reaspiration) works well for many cases. Surgery is needed for large cysts or those in vital organs. The severe form requires surgery plus long-term medication and is fatal without treatment.

Prevention focuses on regular dog deworming and preventing dogs from eating infected livestock organs. A sheep vaccine is available in some areas but there is no human vaccine. Hand washing, clean water, and avoiding contaminated food reduce infection risk.

＊Note: While categorized as a "Once common in Japan," echinococcosis has not been completely eradicated. Infections continue to occur, mostly centered in Hokkaido.