Tapeworms belong to a group of worms called cestodes. They are found in Asia and Africa and occur in areas with poor sanitation. Humans become infected when they consume eggs and larvae of the tapeworm host. Tapeworms species include Diphyllobotrium latum, which is the fish tapeworm; Taenia saginata, the beef tapeworm; and Taenia solium, the pork tapeworm. Tapeworms live in the intestines of humans and may grow from 15 to 30 feet in length, according to the Merck Manual Online Medical Library.
The Basics
The tapeworm has three stages in its life that include eggs, larvae and adult. Adults live in the intestine by attaching to the walls using hooks and suckers. They continue to grow and drop segments of their body containing eggs called proglottids. The eggs are shed in the feces, and the life cycle continues when another organism eats the eggs. Food and water are the most common sources of egg contamination in countries with poor hygiene standards. When the eggs enter the intestines, they hatch and develop into larvae that become mobile. If the larvae become mobile outside the intestine, they form cysts in organs such as the lungs and liver. This is known as an invasive infection.
Symptoms
Symptoms depend on the area of infection, according to the Mayo Clinic. Intestinal infection symptoms include diarrhea, abdominal pain, loss of appetite, nausea, weakness, weight loss and poor absorption of nutrients. Invasive infection symptoms are more serious and include allergic reaction to larvae, fever, seizures, fever, bacterial infections, cyst masses/lumps and neurological problems such as seizures.
Diagnosis
The primary method of diagnosis is checking the feces for eggs and segments under the microscope. This may have to be done several times because eggs are not passed all the time. Scotch tape may also be used to collect eggs from the anus. Invasive infections require a blood test to detect antibodies against the worm. Imaging tests such as X-rays, ultrasound, MRI and CT scan may be used to physically observe the cysts embedded in tissue.
Treatment
Intestinal adult tapeworm is treated with oral medications such as Praziquantel (Biltricide), Albendazole (Albenza) and Nitazoxanide (Alinia). Eggs are not affected by the drugs, and the stool is usually tested after three months to ensure eggs are not present. Invasive infections are treated by location. Albendazole may be used to shrink cysts, and the doctor may use imaging techniques to monitor effectiveness of treatment. Anti-epileptic drugs are used to treat seizures while anti-inflammatory drugs reduce swelling caused by cysts. Surgery is also an option to remove cysts that are lodged in organs while shunts (tubes) may be inserted into the head to drain fluid if the cysts are lodged in the brain.
Prevention
One should avoid eating undercooked meat, fish and pork. Meat should be well cooked to at least 125 degrees Fahrenheit to kill eggs and larvae. It is vital to wash hands properly before eating and wash all fruits and vegetables with clean water in bad-sanitation areas. Meat should be frozen a minimum of 12 hours and fish should be frozen a minimum of 24 hours to kill eggs and larvae. Finally, feces from humans and livestock should be disposed of safely to avoid further contamination.
