Tapeworm (cestoda) is a class
of parasitic flatworm that can infect human's
digestive tracts. Infection usually occurs through ingesting foodstuff
and water contaminated with tapeworm larvae or cysts.
After it is ingested, the tapeworm cyst travels to the intestine
and develops over a period of 2 months into an adult tapeworm,
which can live for years. The adult tapeworm attaches itself to
the walls of the intestine by using suckers and hooks found in
its head region or scolex.
Scolex or head of the tapeworm. Notice the
hooks it uses to attach itself to the intestinal wall.
What Are The Different Types Of Tapeworm?
There are six types of tapeworm infections, classified by their
- Beef tapeworm (Taenia saginata)
This tapeworm comes from cows, and can be found wherever there
is cattle farming. Humans who eat undercooked beef that has
worm cysts can get infected. Beef tapeworm can grow up to 25
feet in length inside the human intestine.
Taenia saginata or beef tapeworm
- Pork tapeworm (Taenia solium)
Although rare in the North America, this type of adult tapeworm
infection is common in South America (including Mexico), Eastern
Europe, India, China, and Southeast Asia.
In addition to eating undercooked pork, a person can also get
infected by eating or drinking contaminated food and water,
as well as by hand-to-mouth contact after touching something
that contains the tapeworm cysts.
Pork tapeworm can grow up to 21 feet inside the intestine.
In a disease called cysticerci, pork tapeworm
larvae or cysts penetrate the intestine and travel through the
bloodstream and infect various organs, such as the brain, spinal
cord, muscles, and even eyes. In this disease, symptoms can
occur months or even years after the initial infection and can
be difficult to diagnose.
- Fish tapeworm (Diphyllobothrium latum)
This type of tapeworm infection can be found in Europe, Japan,
North and South America, as well as in certain parts of Africa.
Fish tapeworm infection occurs by eating raw or undercooked
freshwater fish, including salmon. Inside the intestine, it
can grow up to 25 feet in length.
- Rodent tapeworm (Hymenolepis nana)
This type of tapeworm infects humans through an intermediate
carrier, such as fleas, beetles, and cockroach that carry the
cysts. Rodent tapeworm can grow up to 20 inch long in the intestine.
- Dog tapeworm (Dipylidium caninum)
Similar to rodent tapeworm, dog tapeworm can infect humans,
usually children, who accidentally ingest infected flea or louse.
It can grow up to 24 inch.
- Dwarf tapeworm (Hymenolepis nana)
Unlike other tapeworms, the native host of dwarf tapeworm is
man. It infects another human through ingestion of food contaminated
with feces. Dwarf tapeworm is the smallest of all other worms,
and can grow up to 12 inch in the intestine.
Symptoms of Tapeworm Infection
The symptoms of tapeworm infection are:
- Abnominal pain or discomfort
How Is Tapeworm Infection Diagnosed?
Your doctor would perform the following tests:
- Blood test
Signs of tapeworm infections include elevated levels of eosinophil
(a type of white blood cell), presence of large and pale red
blood cells, vitamin B12 deficiency.
- Stool test
Tapeworm segments in the stool can be detected by a microscope.
Prevention of Tapeworm Infection
Tapeworm infection can be prevented by:
- Washing your hands when preparing food
- Not eating undercooked or raw food
Avoid sushi, fruit, salad, and even ice when traveling to areas
known to have tapeworm outbreaks.
Treatment For Tapeworm Infection?
Your doctor may prescribe the following medications:
Prescribed to eliminate the tapeworm infection, antihelminthics
such as niclosamide and praziquantel, have a very high success
rate of over 95%. Usually, segments of tapeworm start to be
shed in the feces within 48 hours of taking these medications.
After a round of antihelminthics, your doctor may prescribe
a gentle laxative to help purge segments of killed tapeworm
from the intestine.
Treated properly, the prognosis for tapeworm infection is very
good. If no tapeworm segment is found in the stool 4 months after
the initial treatment, the person is cured.
- eMedicine article