Tapeworm Disease.
Taeniases.
P.K. Ghatak, MD
Tapeworm infestation of humans was a universal disease in the old world but improving the public health measures and general sanitary practices have eliminated this infestation from most of the countries of the world except the tropical/subtropical poor nations.
Tapeworm belongs to the flatworm group. Adult tapeworms are usually 15 to 30 feet long. It has three distinct parts of the body – head, neck, and segmented body. The head, under the microscope, looks like an ugly monster with hooks and suckers. The body is segmented and each segment of the body is self-sufficient in reproductive units and it contains multiple eggs. The last few segments are shed in the feces and eliminated from the body during defecation.
Humans are infected with these species of tapeworms: Taenia solium (pork tapeworm), Taenia saginata (beef tapeworm), Diphylloborthium latum (fish tapeworm), Taenia asiatica (Asian tapeworm) and Hymenolepsis nana (dwarf tapeworm).
Tapeworms are responsible for two distinct illnesses in humans.
A. Cysticercosis.
B. Intestinal Tapeworm disease. Not all the worms listed above cause both diseases but Taenia solium does.
Cysticercosis:
Cysticercosis is a serious illness due to the development of multiple cysts in the brain and eyes. Cysts may also develop in other organs but called by different names, for example, echinococcosis is a cyst in the lungs.
Mode of infection.
This is primarily due to the contamination of food and drinks by human feces from bad sanitary practices by the individual leading to self infection, or, from others like cooks or food handlers.
The ingested eggs in the intestine transform into spherules penetrate the wall of the small intestine and enter the blood circulation. The circulation takes them to other organs. In the brain or eyes, the spherules develop a thick wall and secrete fluid within the cavity, and the cysts are known as Cyticerca. Most of the time, the cysts produce daughter cysts and cluster together. This causes an increase in intracranial pressure and the patient develops seizures. In the eyes, the cysts produce blindness.
Other neurological symptoms develop from damaged brain tissue by the cysts, and symptoms depend on the location of the brain cysts.
Diagnosis:
The cysticerci are easily diagnosed by MRI of the brain.
Treatment is anti-seizure medication for epilepsy followed by surgery. During surgery, care should be taken not to nick the cysts. The cystic fluid is very allergenic and can produce anaphylaxis, and daughter cysts will spread further.
Intestinal tapeworm disease.
This is the usual life cycle of the tapeworm.
When humans consume poorly cooked pork containing tapeworm cysts, the digestion of meat frees the cysts from the muscle. The cysts just open up and invaginate and attach themselves to the intestinal wall and begin to draw nutrition from the host and mature into adult worms. A tapeworm usually lives 7 to 10 years. And begins producing segments full of eggs within a short few months after entering the GI tract of the host.
Consequences of Tapeworm infestation of intestine.
Most patients are not aware of the presence of the worms. However, children show signs of malnutrition and nutrient deficiencies. Occasionally the worm can enter the bile duct or pancreatic duct and cause Choledochocystitis or pancreatitis respectively. Similarly, appendicitis and diverticulitis bowel rupture and peritonitis also occasionally occur.
Diagnosis:
Stool examination detects the characteristic eggs of the tapeworms.
Treatment – Drug treatment is very effective and these 3 drugs are often used. Praziquantel, Albendazole and Nitazoxanide. Praziquantel is the preferred drug because it completely dislodges the parasite from the intestinal wall.
Prevention is essential and is very effective and costs practically nothing. Public education and proper handwashing with soap and water can wipe out intestinal tapeworm disease, and properly cooked meat and pork can control the spread of cysticercosis.
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