2. Tapeworm Facts
The tapeworm eats whatever the host eats. It lives in the internal
organs of the host. In addition, tapeworms can be less than 1 inch but
they can grow up to 16 feet!
Fun Facts:
o All tapeworms have male and female segments.
o The pork tapeworm lays its eggs in the host’s face.
o Tapeworms lay their eggs in the meat of the animal you would eat.
o Most of the invasions happen in poor countries.
o A tapeworm can live in a host for over 10 years without the host
knowing.
o Hosts become infected by eating undercooked meat that has cysts
in it.
4. Taenia Saginata
Taenia Saginata: Beef Tapeworm/ Hookless Tapeworm
o The beef tapeworm is a parasite of both cattle and humans.
o The beef tapeworm is normally 4 to 10 meters in length, but can grow
over 12 meters long.
o It is whitish in color.
o The strobila is composed of a series of ribbon-like segments
called proglottids.
o The segments are made up of mature and gravid proglottids.
o The eggs are in the proglottids and they are only going to infect the
cattle. If a human eats the eggs, it will not cause any infection. The
human is only infected by eating the beef containing the larvae.
o The segments are eliminated individually through the human feces.
o T. saginata is the largest of genus Taenia consisting between 1000 to
2000 proglottids and can also have a lifespan of 25 years in a host's
intestine.
o The disease is called Teaniasis and the symptoms are weakness, weight
loss, epigastric pain, appetite loss, anal obstruction, and anal itching
produced when the proglottids are coming out.
7. Taenia Solium
Taenia Solium: Pork Tapeworm/ Hook Tapeworm
• T. solium is normally 2 m to 3 m in length, but can become very large, over 50 m long in
some situations.
• It has 800-900 proglottids.
• The proglottids are expulsed in groups of 5 or 6.
• Humans and pigs get infected by eating these eggs, and the human is also contaminated
by eating raw pork containg larvae.
• T. solium has a very similar life cycle to Taenia saginata.
• These parasites can cause Taeniaosis , causing moderate abdominal pain. If the eggs
contaminate any organ or tissue, it is called cysticercosis. If the eggs travel to the central
nervous system, it is called neurocysticercosis.
• Infection with T. solium adults is treated with niclosamide, which is one of the most
popular drugs for adult tapeworm infections, as well as for fluke infections.
• As cysticercosis is a major risk, it is important to wash one's hands before eating and to
suppress vomiting if a patient may be infected with T. solium. If neurocysticercosis occurs
the drug of choice is either albendazole or praziquantel. These drugs damage the
parasites skin internally causing it to disintegrate and is then removed by the
host's immune system.
• Infection may be prevented with proper disposal of human feces around pigs, cooking
meat thoroughly and/or freezing the meat at −10 °C for 5 days. Most cases occur because
infected food handlers contaminate the food.
10. Human Cysticercosis
Cysticercosis refers to tissue infection after
exposure to eggs of Taenia solium, the
pork tapeworm.
Symptoms: The symptoms vary according to
where the cysticercosis are located, the
number of parasites, and the immune host
response. The most frequent symptoms are:
headaches, seizures, blurred vision, and lymph
nodes swelling.
13. Hymenolepsis Nana
Hymenolepsis Nana: Dwarf Tapeworm
• Dwarf tapeworm (Hymenolepis nana, previously known as Vampirolepis
nana, Hymenolepis fraterna, and Taenia nana) is a cosmopolitan species that is one of
the most common cestodes of humans in the world, especially among children.
• It can be found throughout the world, but is usually most common in temperate zones.
• It is the most common cestode of humans and is found wherever there are human
inhabitants.
• As its name implies, it is a small species, exceeding 40 mm long and 1 mm wide.
• The scolex bears a retractable rostellum armed with a single circle of 20 to 30 hooks.
The scolex also has four suckers, or a tetrad.
• The neck is long and slender, and the segments are wider than long.
• This is the only cestode that can complete its life cycle in one host: a human.
• The human can store the not only the adult, but larvae parasites.
• It has about 200 proglottides.
• The scolex has 4 suckers with a crown that has 20-30 hooks.
• The eggs are round and similar to Taenia Saginata.
14. Hymenolepsis Nana
Developement:
Infection can be direct or indirect.
Direct is infection is acquired most commonly from eggs in the feces of another
infected individual, which are transferred in food, by contamination. Eggs hatch in
the duodenum, releasing oncospheres, which penetrate the mucosa and come to
lie in lymph channels of the villi. Oncospheres develops into a cysticercoid which
has a tail and a well formed scolex.
The indirect life cycle is doubtless a recent modification of the ancestral two-host life
cycle, found in other species of hymenolepidids, because cysticercoids of H.
nana can still develop normally within larval fleas and beetles.
Direct contaminative infection by eggs is probably the most common route in human
cases, but accidental ingestion of an infected grain beetle or flea cannot be ruled
out.
The direct infectiousness of the eggs frees the parasite from its former dependence
upon an insect intermediate host, making rapid infection and person-to-person
spread possible. The short life span and rapid course of development also facilitate
the spread and ready availability of this worm.
