Echinococcus is an infection caused by the Echinococcus granulosus or Echinococcus multilocularis worm.

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. However, 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 - 20 years until it is large enough to be felt by physical examination.
Symptoms include:
Pain in the upper right part of the abdomen
Bloody sputum
Chest pain
Cough
Fever
Severe skin itching

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:
Abdominal CT scan or ultrasound
Abdominal X-ray
Blood test
Chest x-ray
Liver function tests
Thoracic CT scan or ultrasound
Most often, echinococcosis is found when an imaging test is done for another reason.

Treatment
Many patients can be treated with albendazole or mebendazole. These medications are often used for up to 3 months. Another drug, praziquantel, may be helpful combined with albendazole or mebendazole.
The cysts may be removed with surgery, if possible. This can be a complicated surgery.