Tapeworms in Humans. Symptoms. Treatment. Life Cycle. Prevention

What are tapeworms?

Tapeworms are long, flat, ribbon-shaped, intestinal worms found in the intestines of vertebrates. The term tapeworm is commonly restricted to members of the class Cestoidea. The tapeworms (cestodes) Taenia saginata (beef tapeworm) and Taenia solium (pork tapeworm) are of significance to human beings as taeniasis occurs when human beings eat raw or undercooked, unfrozen beef or pork.

Of note is the life-threatening condition called cysticercosis (cysticercus disease), a disease caused by encystment (trapped bubbles) of cysticercus larvae of tapeworms in subcutaneous, muscle, or central nervous system tissues. Cysticercosis is typically developed in swine and cattle, producing measly pork and beef. Whereas in humans, it results from the hatching of the eggs of Taenia solium in the intestines or by accidental ingestion of eggs from human feces. Encystment in the brain may cause serious nerve damage and can be life threatening and encystment in the eye (usually the rear chamber) may cause ophthalmic damage.

What are the symptoms of tapeworm infestation?

Beef tapeworm infections produce only mild symptoms that may include diarrhea, abdominal pain, and weight loss. Pork tapeworm infections generally produce no symptoms. Another sign of having tapeworms can be if pieces of the tapeworm break apart (proglottids) and come out through the feces. Cysticercosis, however, can cause muscle pain, weakness, and fever. If it involves the central nervous system, it can also cause epilepsy or inflammation of the brain and the membranes around it. Severe tapeworm infection in humans causes anemia due to the lack of vitamin B-12, which the tapeworm absorbs through the lining of the gut.

Prevalence of tapeworms

Both species viz., Taenia saginata and Taenia solium are worldwide in distribution. Taenia solium is more prevalent in poorer communities where humans live in close contact with pigs and eat undercooked pork.

Echinococcus, another genus of the tapeworms, which causes hydatid disease, prevails in sheepherders living closely with their infected dogs.

Similarly, fish tapeworms prevail in the coastal region and in the regions of fish consumption.

Life cycle of tapeworms

Human beings are the only definitive hosts for Taenia saginata and Taenia solium, containing the adult, sexually-reproducing stage. Eggs or gravid proglottids pass with the feces. The eggs can survive for days to months in the environment. Cattle and pigs become infected with Taenia saginata and Taenia solium respectively by ingesting vegetation contaminated with eggs or gravid proglottids. In the animal’s intestine, the hexacanths hatch, invade the intestinal wall, and migrate to the striated muscles, where they develop into cysticerci. Altogether, a cysticercus can survive for several years in the animal.

How do you get tapeworms?

Humans become infected by ingesting raw or undercooked infected meat. In the human intestine, the cysticercus develops over two months into an adult tapeworm, which can survive for years. The adult tapeworms attach to the small intestine by their scolex and reside in the small intestine. The adult parasitic worms produce proglottids which mature, become gravid, detach from the tapeworm, and migrate to the anus or pass in the stool. The gravid proglottids release the eggs after the proglottids pass with the feces.

When this cycle is short circuited by a human by directly ingesting the eggs instead of a pig (which can occur in regions with poor sanitation), cysticerci can develop in human flesh too which may form large cysts (bubbles), often in the brain, which can be life threatening.

Are tapeworms contagious?

No, not that severe. However, in poor sanitary conditions ingestion of eggs can happen instead of infestation from the meat.

Prevention and treatment of tapeworms

• Prevention of tapeworm infestation is by thoroughly cooking meat and fish until juices run clear and the centers are no longer pink. This destroys any tapeworm cyst in the meat and fish.
• Always avoid rare meat and fish. The heat taken to properly cook meat and fish kills the tapeworms.
• Ensure clean drinking water.
• Ensure good personal hygiene and eating habits. Keep hands always clean. Trim nails. Wash hands before eating or preparing food. Wash hands after a toilet visit. Generally, any anti-bacterial soap will ensure a worm-free existence. Emphasize the importance of washing hands to children.
• So, discourage children from sucking thumb and biting nail.
• Consequently, deworm regularly or as directed by your primary physician.

Tapeworm synonyms

Cestodes.

Diagnosis of tapeworm infestation

Microscopic examination of stool samples will reveal eggs and proglottids. To diagnose cysticercosis, examine the muscles, brain, or the part involved with a CT or MRI scan. It will show cysts. Furthermore, blood tests for antibodies can confirm the diagnosis.

Medications for treating tapeworm infestation

Conventional drug options are quinacrine hydrochloride (atabrine hydrochloride) or niclosamide. Furthermore, tapeworm cysts will require two separate drugs, praziquantel, and albendazole. Talk to your doctor for more information and appropriate dosages and intervals.