Hydatid disease in a zoonosis is caused by the cystic stage of the parasite
E granulosus. Hydatid disease is endemic in sheep farming and cattle farming areas of Asia, North and East Africa, South America, Australia and the Middle East.
2 Dogs and other carnivorous animals are definitive hosts, while sheep, cattle, horses and goats are intermediate host. Humans are an accidental and dead-end intermediate host. Humans acquire infection through contact with a definitive host or by consuming contaminated water or food. Apart from the common sites such as liver (55–60%) and lungs (30%), hydatid cysts can present at unusual sites, which include kidney (2.5%), heart (2.5%), bones (2%), muscles (1%), brain (0.5%)
1 and spleen (1.5%).
Other rare sites include omentum, ovaries, parametrium, pelvis, thyroid, orbit and retroperitoneum.
1 Clinical presentation of hydatid disease depends on the site of the lesion. Hydatid disease may present with complications inducing rupture of the cyst leading to anaphylactic shock or formation of localised or generalised 2
0 echinococcosis.
3 Ultrasonography and CT scan are helpful in the pre-operative diagnosis of a hydatid cyst. Serological tests, such as immunoelectrophoresis, ELISA, latex agglutination and indirect haemagglutination test, etc are supportive. The principal treatment is surgical. However pre- and postoperative courses of albendazole and praziquantel should be considered in order to sterilise the cyst and, thus, reduce the chances of anaphylaxis and recurrence.
Learning points- Hydatid cysts can affect any organ in the body. Unusual locations and clinical presentations may pose diagnostic and therapeutic challenges; therefore, a high index of suspicion of this disease is justified in any cystic lesion of any organ of the body especially in endemic regions.
- Medical treatment should proceed and follow the surgical intervention in order to prevent complications and recurrences.