Tapeworm infections can occur「not without reason」and perhaps due to「a fault」: eating unwashed raw vegetables, uncooked or undercooked meat (CAUTION: always fully-cook your tapeworms and their eggs before eating them) or from preparing and eating food with unwashed hands after defecating, spreading an infection among dinner guests:
　「Tapeworm eggs are generally ingested through food, water or soil contaminated with human or animal (host) feces. For example, if a pig is infected with a tapeworm, it may pass eggs or segments (proglottids) of the adult tapeworm through its feces into soil. Each segment contains thousands of microscopic tapeworm eggs. These eggs can be ingested via food contaminated with the feces. Once the eggs have been ingested, they develop into larvae, which can migrate out of the intestines and form cysts in other tissues such as the lungs or liver. …Tapeworm infection can also be caused by eating raw or undercooked meat from an animal or a fish that has the larval form of the tapeworm cysts in its muscle tissue. Once ingested, the larvae then develop into adult tapeworms in the intestines. Adult tapeworms can measure up to 50 feet (15 m) long and can survive as long as 20 years. Some tapeworms attach themselves to the walls of the intestine, where they cause irritation or mild inflammation, while others may pass through to the stool and exit the body. Unlike other tapeworms, the dwarf tapeworm can complete its entire life cycle — egg to larva to adult tapeworm — in one host. This is the most common tapeworm infection in the world and can be transmitted between humans. Even while being treated for certain tapeworm infections, reinfection can result from ingesting tapeworm eggs shed by the adult worm into the stool, as a result of insufficient personal hygiene.」
　　[　https://en.wikipedia.org/wiki/Tapeworm_infection 2013-09-14　]　

Modern definitions (that generally disregard history) …excluding politically incorrect concepts and other meanings deemed offensive today; may list only pigeonholed definitions, euphemisms, or meaningless mnemonics)
Chinese: variant of 蛔
Unihan extended: tapeworm
EDRDG: tapeworm