什麼是絛蟲

扁形動物門絛蟲綱一種身體兩側對稱的寄生性扁蟲，約3,000種，呈世界性分佈。體長從約1公釐到15公尺餘。頭節上有吸盤，通常還有鈎，用於固着在宿主的肝和消化道內。一旦固着成功，就通過其表皮吸收食物。整個軀體大體分為數段：頭或頭節，上有吸盤和鈎；不分段的頸；以及一列形狀相同的節片（具備雌雄生殖器官的身體部件）。節片由頸底部的一個生長區連續生成。受精後內含數千個胚體的成熟節片爆裂，隨宿主糞便排出。整個生命週期可能需要不止一個宿主，但一般説來會與旋毛蟲的生命週期十分相像。多種以人為宿主的絛蟲屬於帶絛蟲類；其中間宿主則可從其學名中辨識（如牛帶絛蟲是以牛為中間宿主）。在美國東南部，人被絛蟲寄生的現象頗為常見；人被絛蟲感染的途徑主要是接觸了受到污染的土壤或水，以及食用了烹煮不充分的肉和魚。

tapeworm

Any of about 3,000 species (class Cestoda, phylum Platyhelminthes) of bilaterally symmetrical parasitic flatworms found worldwide. Tapeworms range from 0.04 in. (1 mm) to more than 50 ft (15 m) long. The head bears suckers and often hooks for attaching to the liver or digestive tract of the host. Once attached, tapeworms absorb food through their body wall. The body is often divided into a head or scolex possessing the suckers and hooks, an unsegmented neck, and a series of proglottids (units containing both male and female reproductive organs) which continually form in a growth region at the base of the neck. Following fertilization, each mature proglottid containing thousands of embryos breaks off and is eliminated in the host's feces. The life cycle may require more than one host but otherwise somewhat resembles that of the roundworm trichina. Many species that infest humans belong to the genus Taenia; the intermediate host is implied by the name (e.g., beef tapeworm, T. saginata). Human infestation is common in the southeastern U.S.; humans usually acquire tapeworms through fecal contamination of soil or water or inadequate cooking of meat or fish.