The genus<unk>  includes six  species of cyclophyllid tapeworms to date, of the family Taeniidae. Infection with<unk>  results in hydatid disease, also known as<unk> is.
In humans, this causes a disease called<unk> is. Latency can be up to 50 years, and is mostly found in South and Central America, the Middle East, China, and the West of the U.S.A. (e.g.. Arizona, New Mexico and California).
Human<unk> is (hydatidosis or hydatid disease) is caused by the larval stages of cestodes (tapeworms) of the genus<unk> .<unk>  granulosus causes cystic<unk> is (CE), the form most frequently encountered; E. multilocularis causes alveolar<unk> is (AE); E. vogeli causes polycystic<unk> is; and E. oligarthrus is an extremely rare cause of human<unk> is.<unk>  eggs contain an embryo that is called an oncosphere or hexcanth. From the embryo released from an egg develops a hydatid cyst, which is able to survive within organs for years.<unk>  adult worms develop from protoscolices and are typically 6mm or less in length and have a scolex, neck and typically three proglottids.<unk>  eggs contain an embryo that is called an oncosphere or hexcanth. The name of this embryo stems from the fact that these embryos have six hooklets. The eggs are passed through the feces of the definitive host (dogs and other carnivores) and it is the ingestion of these eggs that lead to infection in the intermediate host (sheep, cattle, horses, and camel).
From the embryo released from an egg develops a hydatid cyst, which grows to about 5–10 cm within the first year and is able to survive within organs for years. Cysts sometimes grow to be so large that by the end of several years or even decades, they can contain several liters of fluid. Once a cyst has reached a diameter of 1 cm, its wall differentiates into a thick outer, non-cellular membrane, which covers the thin germinal epithelium. From this epithelium, cells begin to grow within the cyst. These cells then become vacuolated and are known as brood capsules, which are the parts of the parasite from which protoscolices bud. Often, daughter cysts will also form within cysts.<unk>  adult worms develop from protoscolices and are typically 6mm or less in length and have a scolex, neck and typically three proglottids, one of which is immature, another of which is mature and the third of which is gravid (or containing eggs). The scolex of the adult worm contains four suckers and a rostellum that has about 25-50 hooks.
The major morphological difference among different species of<unk>  is the length of the tapeworm. E. granulosus is approximately 2 to 7 mm while E. multilocularis is often smaller and is 4 mm or less. On the other hand, E. vogeli is found to be up to 5.6 mm long and E. oligarthus is found to be up to 2.9 mm long. In addition to the difference in length, there are also differences in the hydatid cysts of the different species. For instance, in E. multilocularis, the cysts have an ultra thin limiting membrane and the germinal epithelium may bud externally. Furthermore, E. granulosus cysts are unilocular and full of fluid while E. multilocularis cysts contain little fluid and are multilocular. For E. vogeli, its hydatid cysts are large and are actually polycystic since the germinal membrane of the hydatid cyst actually proliferates both inward, to create septa that divide the hydatid into sections, and outward, to create new cysts. Like E. granulosus cysts, E. vogeli cysts are filled with fluid.
Echinococcus
Blastocystis
Acanthamoeba
Corpus albicans
Cryptosporidium
Monilethrix
Rhizopus
Candida 