Hydatidosis: Dynamics of Transmission

Abstract

Hydatidosis is a widespread zoonosis infecting a large number of animals and humans. Echinococcus granulosus has the smallest taenia adult of the cestodes but with the largest larva. Its morphologic and biologic features were identified with DNA analysis. Different strains were separated according to the intermediate hosts: sheep, cattle, pigs, horses, camels. Definitive host are canids, mostly dogs, where the worm grows to adulthood in several months. The eggs are scattered in the pasture by wind and water and are ingested by various hosts. The larvae migrate through the intestinal wall and penetrate the organs, mostly liver and lungs. The eggs survive several days outside, depending on the temperature, but numerous eggs die in nature because they cannot resist desiccation and extreme temperatures. Dissemination is accomplished by dogs. In Turkana (Kenya) the incidence of hydatidosis is high because of the close relationship between the population and dogs and the habit of leaving their dead bodies in the grasslands. In rural areas, the custom of slaughtering sheep at home, among the dogs, is an important dissemination factor. The circumstances of transmission vary according to the country. In Europe the natural life cycle of E. granulosus granulosus involves dogs as the definitive host and sheep as the intermediate host. In northern Europe E. granulosus borealis infects the canids and deer. E. granulosus canadensis infects wolves and reindeer, but there are no human cases. In the endemic Mediterranean area, sheep and dromedaries are the intermediate hosts. In South America, the life cycle of E. granulosus develops among several definitive and intermediate hosts. Hence the dynamics of transmission vary according to the countries with different hosts.

Unusual site of recurrent musculoskeletal hydatid cyst: Case report and brief review of the literature

“…The cysts contained purulent material. The wound was drained for 24 h. The surgical Table 1 Reported sites of intramuscular infection and bone, liver or lung involvement [2,3] specimen was submitted for histopathological examination which confirmed the diagnosis. The postoperative course was uneventful and the patient was discharged on the 6 th postoperative day.…”

“…Merkle et al [2] 8 Iliopsoas, left adductor musculature, left femur, left medial gluteal muscle, musculature of right upper leg…”

“…The adult worms produce eggs that are released with the feces and spread in various ways, such as through the wind, water or flies [2] . After ingestion by the host, the embryos migrate through the intestinal wall and are either arrested in the capillary bed of the liver developing into liver cysts, or manage to penetrate into systemic circulation thus ending up in remote organs.…”

Diagnostic Dilemma: Analysis of 11 Cases of Hydatid Disease

“…Herbivorların barsaklarında yumurtalar açılır ve parazit barsak duvarına penetre olarak portal ven yoluyla karaciğere gelir ve burada hidatik kist oluşmaya baş-lar. Karaciğer bariyerini geçenler akciğer ve diğer tüm organlara yerleşebilirler (1).…”

Mesenteric hydatid cyst: An unusual presentation

“…Although liver (75%) and lung (15%) are the most commonly involved organs, the disease can be seen anywhere in the body (10%) [1,2]. Bickers [3] after reviewing 532 cases of hydatid disease from an endemic area over a 20 year period recorded only 12 instances of hydatid cyst in pelvis.…”