A 40-year old veterinarian presented with complaints of abdominal pain. On examination he was found to be icteric, the liver was palpable, ultrasonography revealed the presence of cyst in the right lobe of liver. The antigen used to perform the skin test is sterlized using the -

Clinical features A hydatid cyst is typically acquired in childhood and, after growing for years, may cause pressure symptoms. These vary, depending on the site involved. In nearly 75% of patients with hydatid disease, the right lobe of the liver is invaded and contains a single cyst. In others, a cyst may be found in lung, bone, brain or elsewhere. Investigations The diagnosis depends on the clinical, radiological and ultrasound findings in a patient that has close contact with dogs in an endemic area. Complement fixation and ELISA are positive in 70-90% of patients. Management and prevention Hydatid cysts should be excised wherever possible. Great care is taken to avoid spillage and cavities are sterilised with 0.5% silver nitrate or 2.7% sodium chloride. Albendazole (400 mg twice daily for 3 months) should also be used and is often combined with PAIR (percutaneous puncture, aspiration, injection of scolicidal agent and re-aspiration). Praziquantel (20 mg/kg twice daily for 14 days) also kills protoscolices perioperatively. Prevention is difficult when there is a close association with dogs. Personal hygiene, satisfactory disposal of carcasses, meat inspection and deworming of dogs reduces the prevalence of disease. Ref Davidson edition23rd pg 299