Taeniasis is an infection within the intestines by adult tapeworms belonging to the genus Taenia.[ Segments of tapeworm may be seen in the stool.][
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Types of Taenia that cause infections in humans include Taenia solium (pork tapeworm), Taenia saginata (beef tapeworm), and Taenia asiatica (Asian tapeworm).[ Taenia saginata is due to eating contaminated undercooked beef while Taenia solium and Taenia asiatica is from contaminated undercooked pork.][ Diagnosis is by examination of .]
Prevention is by properly cooking meat.[ Treatment is generally with praziquantel, though niclosamide may also be used.][ Together with cysticercosis, infections affect about 50 million people globally.][ In the United States fewer than 1,000 cases occur annually.][
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Signs and symptoms
Taeniasis generally has few or no symptoms.[ It takes about 8 weeks from infection for adult worms to form and can last for years without treatment.]
Infection may be suspected when a portion of the worm is passed in the stool.[ It is not generally fatal.]
Pork tapeworm
Infection in the intestines by the adult T. solium worms is normally asymptomatic. Heavy infection can result in anaemia and indigestion.
A complication, known as cysticercosis, may occur if the eggs of the pork tapeworm are eaten. This typically occurs from vegetables or water contaminated by feces from someone with pork tapeworm taeniasis. The eggs enter the intestine where they develop into which then enter the bloodstream and invade host tissues. This is the most frequent and severe disease caused by any tapeworm. It can lead to headaches, dizziness, , dementia, hypertension, lesions in the brain, blindness, tumor-like growths, and low eosinophil levels. It is a cause of major neurological problems, such as hydrocephalus, paraplegy, meningitis, and death.
Beef tapeworm
Taenia saginata infection is usually asymptomatic, but heavy infection causes weight loss, dizziness, abdominal pain, diarrhea, , nausea, constipation, indigestion, and loss of appetite. It can cause antigen that induce allergic reaction.
Asian tapeworm
Taenia asiatica is also usually asymptomatic. It is unclear if T. asiatica can cause cysticercosis.[
In pigs, the cysticercus can produce cysticercosis. develop in liver and . ( T. saginata does not cause cysticercosis.)]
Transmission
Taeniasis is contracted after eating undercooked pork or beef that contains the . The adult worms develop and live in the lumen of the intestine. They acquire nutrients from the intestine. The gravid proglottids, body segments containing fertilised eggs, are released in the faeces.
If consumed by an intermediate host such as a cow or pig, they hatch within the duodenum to become larvae, penetrate through the intestinal wall into nearby , and enter the bloodstream. Once they reach organs such as the skeletal muscles, liver, or lungs, the larvae then develop into a cyst, a fluid-filled cysticercus. These contaminated tissues are then consumed through raw or undercooked meat.[
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Cysticercosis occurs when contaminated food, water, or soil that contains T. solium eggs is eaten.
Diagnosis
Diagnosis of taeniasis is mainly using stool sample, particularly by identifying the eggs. However, this has limitations at the species level because tapeworms have similar eggs. Examination of the scolex or the gravid can resolve the exact species.
To date the most relevant test for T. asiatica is by enzyme-linked immunoelectrotransfer blot (EITB). EITB can effectively identify asiatica from other taenid infections since the serological test indicates an immunoblot band of 21.5 kDa exhibited specifically by T. asiatica.
Prevention
Prevention efforts include properly cooking meat, treating active cases in humans, vaccinating and treating pigs against the disease, stricter food safety standards, health education, improved sanitation, and improved pig-raising practices.[
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Preventing human faeces from contaminating pig feeds also plays a role. Infection can be prevented with proper disposal of human faeces around pigs, cooking meat thoroughly and/or freezing the meat at −10 °C for 5 days. Contaminated hands are the primary method of transmission for human cysticercosis, especially in populations like food handlers.[
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Proper cooking of meat is an effective prevention. For example, cooking (56 °C for 5 minutes) of beef viscera destroys cysticerci. Refrigeration, freezing (−10 °C for 9 days) or long periods of salting is also lethal to cysticerci.[
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Treatment
Praziquantel is the treatment of choice.[ One study showed albendazole is effective against animal beef tapeworm cysticercosis.]
Epidemiology
The total global infection is estimated to be between 40 and 60 million people.
Regions
Taeniasis is predominantly found in Asia, Africa, and Latin America, particularly on farms in which pigs are exposed to human excrement. At a low level though, it occurs everywhere where beef and pork are eaten, even in countries with strict sanitation policies such as the United States. Taenia saginata is relatively common in Africa, some parts of Eastern Europe,
See also
External links
