Global Health Travel Health Tropical Medicine

Tapeworms 101

Tapeworm 4 meters longDuring my last shift at work I had a patient with a complaint of diarrhea, abdominal pain and “an animal coming out from down there”.  My patient was a mid-fifty year old hispanic female, born in Guatemala.  She had no other medical history other than a surgery for removal of her gallbladder and appendix.

Fortunately, she had also brought in a plastic bag containing a bit of the “animal” that had protruded from her “bottom”.  This helped dramatically with my diagnosis.  I wanted to do some additional reading on the subject of intestinal parasites and specifically Taneia, also known as “tape worms”.

Taenia Saginata is associated with undercooked beef and Taenia Solium is associated with undercooked pork. The eggs may be found anywhere in the body and can cause seizures if in brain tissue (neurocysticercosis).  The actual worms are typically found in the intestines.

Taenia egg
Taenia Egg

Worldwide, prevalent in areas where undercooked beef or pork are eaten
Transmission/ Incubation:
Acquired by the ingestion of undercooked beef or pork meat that is infected with the larval stage of either species. The patient may be a symptomatic for years before diagnosis.
Adequately cooking beef and pork, education about fecal contamination of soil, water, livestock pens 
Demonstration of eggs or proglottids in fecal smear. The eggs of both species are indistinguishable, only proglottids are different.
Praziquantel is considered first-line and albendazole may be used for neurocysticercosis. Consider steroids for cerebral edema in neurologically symptomatic patient, especially during treatment, as the larvae die.

Diagnosis of Species and Microscopy:

Taenia saginata
Taenia Saginata

Eggs from both species are indistinguishable, when examined under a microscope in a fecal smear.  However, when one examines the proglottids (body parts) the difference can be seen.  T. Saginata has more branches per side, generally more than 12-15. 



Taenia solium
Taenia Solium



 In contrast to T. Sagniata, T. Solium has less branches per side.  The typical T. Solium proglottid has less than 12 branches, versus more than 12 as seen with T. Saginata.  These two different species have different host animals but cause similar conditions in humans.  In fact the exact identification is not always necessary because the treatment for both conditions is the same.   

Tapeworms care acquired from eating raw or partially cooked beef or pork. The animal must be infected with the tapeworm to give it to humans. The humans eat the pork or beef flesh that has larvae (baby tapeworms) inside. Cooking normally kills these larvae, but if the beef or pork has not been heated to an appropriate temperature, the larvae can survive. Once in the stomach and intestine, the worms begin to grow to adulthood. The usual symptoms include upset stomach and diarrhea. The tail of the worm may protrude from the anus of the infected person.

Cysticercosis is also caused by these tapeworms, but does not affect the GI (stomach and intestines) tract.  Instead of eating the larval stage of the tape worm, the person ingests the eggs of the parasite.  These eggs then penetrate the wall of the stomach and spread, via the blood stream, to other parts of the body.  Once laying there, the body puts a protective casing around the worm to try and keep it from spreading.  These little eggs can cause effects like tumors, especially in the brain. seizures are common if the larvae/eggs invade the brain.

Fortunately, prompt medical care and some antiparasitic medicine can treat this infection.  In rural areas where people often lack access to medical care, these infections can go undiagnosed.  Undiagnosed tape worms can be especially damaging to children who may begin to suffer from malnutrition.  This malnutrition is generally due to a decreased ability to absorb nutrients from food, secondary to diarrhea and the actual worm burden. 

For travelers and adventurers, prevention of this infection centers around eating properly cooked meat.  Ensure that your pork dish is not served “medium rare”.  Pink pork should generally have a few more minutes on the heat.  Hand washing and avoiding pork-sushi are always good advice.

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