Important tapeworm parasites of humans
Zainab Waseem
Tapeworms are the parasites in the gut of vertebrates or in derivatives of the gut, as in bile ducts of the liver or in intestinal caeca of birds. Although most species of cestods or tapeworms parasitize wild animals but few of infect humans and animals, therefore they are of specific interest.
All the tapeworms that parasitize and infect humans belong to the orders of Pseudophyllidea and Cyclophyllidea.
Tapeworm infection
Tapeworm infection is caused by consuming food or water contaminated with tapeworm eggs or larvae. When eggs of tapeworms are ingested, they migrate to intestines and there they form larval cysts in body tissues and organs, this term is referred as invasive infection.
If consumption of tapeworm larvae takes place,
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The scolex ,with its four powerful suckers, is followed by a long, slender neck.Mature segments are slightly wider than long ,whereas gravid ones are much longer than wide. The spherical eggs are characteristics of Taeniidae . A thin ,hyaline ,outer membrane is usually lost by the time the egg is voided with the feces.
Life cycle
Taenia saginata causes an infection called taeniasis. It is commonly known as the beef tapeworm or cattle tapeworm owing to cows as their intermediate hosts. Humans are the only definitive hosts. Taeniasis is distributed worldwide and is relatively common in areas of Africa, Eastern Europe, America and the Philippines.
Eggs are passed in the feces of an infected human through proglottid or a tapeworm segment. They can survive a few months out in the environment. If a cow (the intermediate host) consume contaminated vegetation, it ingests mature eggs or gravid proglottids. When humans consume poorly cooked meat, they become infected by the worm. Adults attach to the intestinal wall with their scolex using four