A company executive, who travels worldwide, present with upper abdominal mass and +ve Casoni's test. This could be due to which of the following organism -

Casoni's test: 1. This is an immediate hypersensitivity (Type I) skin test used for diagnosis of hydatid disease which is caused by Echinococcus granulosus. 2. Antigen- 0.2 ml sterile hydatid fluid is injected in arm. 3. Sensitive patients develop 5 mm or large wheal with formation of pseudopodia within 30 min. with no reaction in the control arm. 4. Disadvantage - low sensitivity and false positive results in cross reactive cestode infections.it is obselete nowdays